Table Of Contents I. Sets of Numbers in the Real Number System II

advertisement

Table Of Contents

I.

Sets of Numbers in the Real Number System

II.

Venn Diagrams

III. Subset Definition & Notation of Subsets

IV. Primes and Composites

V.

Tests For Divisibility

VI. Work with Fractions

VII. Operations with Signed Numbers

VIII. Absolute Value

IX. Order of Operations

X.

The Laws of the Real Number System

XI. Using The Laws

XII. Evaluating and Simplifying Algebraic Expression

XIII. The Distributive Law of Multiplication over Addition (Law

5)

XIV. More Laws (6-11)

XV. Using the Laws to Solve Equations

Table Of Contents, continued

XVI. Solving Formulas Using the Laws

XVII. Percent problems

XVIII. A Taste of Geometry

XIX. Solving Inequalities

XX. Chains of Inequalities

XXI. Graphing Two Variable Linear Equations

XXII. Graphing Single Variable Equations in Two Dimensions

XXIII. Graphing Two Variable Equations using Slope Method

XXIV. Nuances

XXV. Find Equations Given Facts

XXVI. Graphing Two Variable 2-D Inequalities

XXVII. Function Notation Introduced

XXVIII. Systems

XXIX. Two Methods of Solving Systems

XXX. Use Systems to Solve Word Problems

XXXI. Geometry Word Problems

Table Of Contents, continued

XXXII.Mixture Word Problems

XXXIII.Distance Word Problems

XXXIV.Graphing Systems of Linear Inequalities in Two

Dimensions

XXXV.Laws of Exponents

XXXVI.Exponent Examples

XXXVII.Expansions on the Schema

XXXVIII.Example of Zero & Negative Exponent Corollaries

XXXIX.Scientific Notation

XL. Operating With Polynomials

XLI. Review for Test VII

XLII.Multiplication of Polynomials

XLIII.Division of Polynomials

XLIV.Five Types of Factoring

XLV.Review of Types

XLVI.Uses of Algebraic Factoring

I

Sets of Numbers in the Real Number System

Natural Numbers

• Verbal definition:

• Symbolic definition:

Whole Numbers

Verbal definition:

• Symbolic definition:

Integers

• Verbal definition :

• Symbolic definition:

“the positive counting numbers”

N = {1,2,3, …}

“the natural numbers together with 0”

W = {0,1,2,3, …}

“ the whole numbers and their opposites”

J = {…-3,-2,-1,0,1,2,3…}

I

Sets of Numbers in the Real Number System, continued

Rational Numbers

• Verbal definition:

• Symbolic definition:

Real Numbers

• Verbal definition:

• Symbolic definition:

“any number that can be expressed as a fraction with an integer numerator, and a nonzero integer denominator”

Q = {p/q  p ∈ J, q ∈ J, q ≠≠≠≠

0 } Read: the set of all p/q such that p is in J, q is in J, and q is not equal to 0.

Irrational Numbers

• Verbal definition:

• Symbolic definition:

“non-terminating, non-repeating decimal. It cannot be written as a fraction with an integer numerator, & denominator.”

H = {x  x ∈ Q} Read: the set of all x such that x is not a member of Q.

“any numbers that are rational or irrational”

R = {x  x ∈ Q U H } Read: the set of all x such that x is a member of “Q union H”

II

Venn Diagrams

Venn diagrams or set diagrams are diagrams that show all hypothetically possible logical relations between a finite collection of sets (groups of things). Venn diagrams were invented around 1880 by John Venn. They are used in many fields, including set theory, probability, logic, statistics, and computer science

A Venn diagram is a diagram constructed with a collection of simple closed curves drawn in the plane. The principle of these diagrams is that classes be represented by regions in such relation to one another that all the possible logical relations of these classes can be indicated in the same diagram. That is, the diagram initially leaves room for any possible relation of the classes, and the actual or given relation, can then be specified by indicating that some particular region is null or is not null.

Source Wikipedia

II

Venn Diagram of Real Number System

R

2/3

-7

Q

J

W

N

H

Non-terminating, non-repeating decimals like

0 1

7 -23

π and e

-5/6

III

Subset Definition & Notation of Subsets

The definition of a subset could be stated: A is a subset of B

(Denoted A

B) if & only if (iff) all elements (numbers) of A are found in B. ( ⊆ is analogous to ≤ )

Ex1) J

Q

Ex2) J ⊆ N

Ex3) N ⊆ J

True

False

True

IV

Primes and Composites

The first hundred natural numbers and their designation

A Prime Number is a natural number greater than 1 that has only itself and 1 as factors

A Composite number is a natural number greater than 1 that is not prime

Factors Numbers that are being multiplied together

(See section VI for two methods of prime factorization)

V

Tests For Divisibility

There are three easy ways to test the divisibility of numbers

1) To test if a number is divisible by 2, look at the last digit.

If it’s even, then the number is divisible by 2.

2) Test for divisibility by 3 by taking the sum of the digits. If the sum is divisible by 3, then the original number is also divisible by 3.

Ex 1. 5280

5

+

2

+

8

+

0

=

15

3) Test for divisibility by 5, by looking at the last digit. If it’s a 5 or a 0, then the number is divisible by 5.

VI

Work with Fractions

a) Mixed numbers are fractions

Ex:

2

3

4

=

11

4 b) When reducing fractions, use prime factorization. You should use divisibility tests. Prime factorize then cancel like factors.

c) Multiplying fractions is a lot easier if you use the prime factorization method.

• First you prime factorize the tops and bottoms.

• Next you will cancel like factors

• Last but not least, you will multiply straight across

Ex of PF method for multiplication

20

18

30

16

=

2

2

3

2

3

5

2

2

2

3

2

5

2

=

25

12 d) There are two methods of prime factorization in arithmetic

1.The Tree Method (Use for numbers < 100) Ex:

Primes in yellow

VI Work with Fractions, continued

2.

2 ) 3760

=

2

5

47 (exponential form) for prime factorization

2 ) 1880

2 ) 940

2 ) 470

5 ) 235

47 e) Division of fractions: (two steps)

1. Invert the back or bottom fraction depending on how problem is written.

2. Next you must multiply using the multiplication rules. (Subheading C)

Ex:

7

8

÷

9

16

=

7

8

16

9

=

14

9 f) Addition and Subtraction of Fractions

To add or subtract, you must

1. get the least common denominator (LCD). In order to do this, you must first prime factorize (PF) the denominators only.

2. the next step is to Get Jealous.

This means you take any prime factors from one denominator that aren’t in the other, and you multiply the entire fraction by the missing primes.

VI

Work with

Fractions, continued

Example of Addition and Subtraction of

Fractions:

VII

Operations with Signed Numbers

a) When multiplying and dividing with signed numbers, if the numbers have like signs the the result will be positive, whereas unlike signs will result in negative answers.

3 (

4 )

=

12

(

7 )

=

7

+

(

18 )

= −

18 b) When doing addition and subtraction with signed numbers, think as if you’re working with money.

Ex1) .

9

+

.

5

+

(

.

2 )

+

(

.

9 )

=

.

3 or

90 cents

+

50 cents

20 cents

90 cents

=

30 cents

Ex2)

(

3 )

14

=

3

14

= −

11

VIII

Absolute Value

(Da Wimpy Way, i.e. this will be explained in a more complicated way in higher math.)

The Absolute Value of a number is it’s distance away from zero on a number line. The symbol to indicate absolute value is

 n

.

Another way to think of it is the number with a positive sign.

3

=

Ex2) 5

7

= −

2

=

2

Ex3)

4 2

7

= −

4

5

= −

4 ( 5 )

= −

20

IX

Order of Operations

1. Do Single Term Exponents first

2. Do all operations within the parentheses or absolute value bars

3. If the result is a single term exponent, go back to rule 1.

4. Do Multiplication before Addition and Subtraction

Ex. 1 (note that terms are separated by + or -)

(

3 )

2 −

4 ( 5

7 )

3

9

4 (

2 )

3

9

4 (

8 )

9

+

32

Notes:

41

We do not do all the exponents first, only those that are single term.

Good algebraic form is done “step under step”.

X

The Laws of the Real Number System

Subtraction can be defined as addition with a negative number

Division can be defined as multiplication with a fraction

Law 1

The Commutative Law of Addition

(com

)

∀ a , b

R a

+

b

=

b

+

a

Changing the order when adding does not affect the answer

If you add two natural numbers the sum will be a natural number

Law 2

The Commutative Law Of Multiplication

(com

)

∀ a , b

R a

b

=

b

a or ab

= ba

Changing the order when multiplying does not affect the answer

A Law can also be called a property or axiom (self evident truth).

The Laws

(continued)

∀ a , b , c

R

Law 3

The Associative Law of Addition

( a

+ b )

(assoc

)

+ c

= a

+

( b

+ c )

= a

+ b

+ c

Changing the grouping when adding does not affect the answer

Law 4:

a , b ,

The Associative Law Of Multiplication

(assoc

) c

R ( ab ) c

=

a ( bc )

=

abc

Changing the grouping when multiplying does not affect the answer

More Laws to come…

XI

Ex1)

( 2

2

(

2

2 x x

3 )

3

+

+ x x

8 x

8 x )

+

6 x

+

+

3

( 6

6

8

8 x x

6

3

)

( 6

3 )

Using The Laws

Given

Assoc +

Comm +

Assoc +

Combine Like Terms (CLT)

When using the associative law, you must be careful of how you write it. The

+ must be outside the parentheses.

Keep the negative sign closely attached to a negative number:

It is okay to write (2x – 8x) + (6 – 3)

It is okay to write (2x – 8x) + (-3 + 6)

It is not okay to write (2x – 8x) – (3 + 6)

XI - Using The Laws, continued

Ex2) 3 x

4

=

5

3 x

3 x

+

+

4

( 4

4

4 )

=

=

4

9

+

3 x

+

0

=

3 x

=

9

9

5

1

3

1

3

3 x

3

 x

=

1 x

=

=

3

1

3

1

3

9

9 x

=

3

Given

⊗ l l of

Inv

Id

Id of

Inv

=

=

(law applied to Given to get this line, etc.) assoc

Note: LHS = left hand side reason, RHS = right hand side reason .

XII

Evaluating and Simplifying Algebraic Expression

y

= −

3 y

= −

3

Evaluate 2 x

3 y

2

2 (

2 )

3 (

3 )

2

4

3 ( 9 )

= −

4

27

= −

31

Evaluate −

5 ( 1

+ x

3

)

1

+ x

5 ( 1

+

(

2 )

3

)

1

2

5 ( 1

8 )

5 (

1

7 )

1

35

1

35

XIII

The Distributive Law of Multiplication over Addition

Law 5

This law can be stated symbolically as follows:

a, b, c,

R a(b + c) = ab + ac

It can also be stated verbally: The result of first adding several numbers and then multiplying the sum by some number is the same as first multiplying each separately by the number and then adding the products.

Source Britannica concise dictionary

The abbreviation of this Law is:

dist

⊗ ⁄ ⊕

Distributive Law of Multiplication over

Addition

(continued)

Ex1) −

3 ( 6

4 x )

3 ( 6 )

+ −

3 (

4 x )

18

+

12 x

Ex2)

2

3

5

6

3 x

+

1

2

2

3

10

18

+

6 x

3

+

2

6

4 x

2

4 x

5

9

5

9

+

+

2 x

1

3

+

+

1

3

2 x

( 2 x

2 x )

5

9

+

3

9

+

0

2

9

XIV More Laws

(Continued)

Law 6

The Additive Identity Law

∀ a

R

(

I.D.) a

+

0

= a

Ex 1) 3

+

0

=

3

Ex 1)

Law 7

The Multiplicative Identity Law

(

I.D.)

∀ a

R 1 a

= a

2 x

2 x

3

3

( 3 x

5 )

=

( 1 )( 3 x

5 )

=

3 x

5

More Laws

(Continued)

Law 8

The Additive Inverse Law (

Inv)

∀ a

R a

+

(

− a )

=

0 a

− a

=

0

+ − =

0

Ex 2)

3 x

− y

+ y

3 x

=

0

∀ a

Law 9

The Multiplicative Inverse Law (

Inv)

R a

1 a

=

1 a

1

1 a

=

1 a a

=

1

Ex 1)

2

3

3

2

=

1

Ex 2)

3

1

3

=

1

∀ a , b , c

R

More Laws

(Continued)

Law 10

The Addition Law of Equality (

Law of =) a

= a

+ c

= b

+ c

Ex 1) if 2

+

9

=

5

+

6 then 2

+

9

+

8

=

5

+

6

+

8

Law 11

The Multiplication Law of Equality (

Law of =)

a , b

Ex 1) if

, c

R if a

= b

2

+

3

=

7

2 then then ac

= bc

3 ( 2

+

3 )

=

3 ( 7

2 )

XV

Using the Laws to Solve Equations

Example 1)

3 x

=

29

1

3

3 x

=

29

1

3

1

3

3

 x

=

29

3

1 x

=

29

3 x

=

29

3

Given

(

Law of =)

(assoc

) and Arithmetic

(

Inv)

(

I.D.)

XV Using the Laws to Solve Equations, continued

Ex 2)

Given

(

Law of =)

(assoc

) & Arithmetic

(

Inv)

(

I.D.)

(

Law of =)

(assoc

) & Arithmetic

(

Inv)

(

I.D.)

XVI

Solving Formulas Using the Laws

Ex 1)

3 x

2

3 x

3 x

3

2

3 y y

=

= x

+ z x

3 x

+ z

( 3 x

3 x )

2 y

= −

2 x

+ z

3

2

( 0 )

− y

= −

2 x

+ z

3

3

2

3

2

 −

⋅ −

2

3

2

3 y

 y

=

=

2 x

3

2

+ z

(

2 x

+

2

3

 y

=

3 x

3

2 z z )

( 1 ) y y

=

=

3 x

3 x

2

3

3

2 z z

Given

Addition Law of Equality

Associative Law of Addition

Additive Inverse

Additive Identity

Multiplication Law of Equality

Associative Law and Distributive Law of of Multiplication multiplication over Addition

Multiplicative Inverse

Multiplicative Identity

XVII Percent problems

(Translation method)

English

Is

Of

Percent

What

Find

Change “What is” to

100 x

=

Math

=

or

100 x

Ex 1) What is 2% of 18 x

=

2

100

18

1

=

1

50

18

1

=

1

25

9

1

=

9

25

When doing a problem like this, it is best to prime factorize these numbers for easier reduction.

XVIII A Taste of Geometry

To find the area of a square, the proper formula is A = s 2

The formula to find the area of a rectangle is

A = LW

Therefore

4’(2’) = 8ft 2

2’

4’

L is the length and

W is the width

To find the perimeter of a square, the formula is P = 4s

The formula to find the perimeter of a rectangle is

P = 2L + 2W

Therefore

4’(2) + 2’(2) = 12’

Ex 1)

2’

XVIII A Taste of Geometry

(Continued)

4’

The formula for the area of a triangle can be expressed:

A

= bh

2

A

=

1

2 bh b = base of the triangle h = height of the triangle

1

2

( 4

′ ⋅

2

)

=

4 ft

2

2’

4’

There is no formula to find the perimeter of a triangle, except for an equilateral triangle. The formula for that would be:

P

= b

3

To find the perimeter of any other triangle, you would follow this:

P

= s

1

+ s

2

+ s

3

A Taste of Geometry

(Continued)

Ex 1) r

=

3 "

The area of a circle can be expressed as:

A

= π r

2

Where r = the radius

To find the circumference of this circle we will use the formula:

P

= π d

Where d = the diameter

C

Therefore the circumference of the circle is

= π

( 6 )

3 .

14 ( 6 )

=

18 .

84 in

π is one of the most commonly used irrational numbers. It is equivalent to the number of times a radius goes around a semi-circle, and is roughly equivalent to

3 .

14 or

22

7

Therefore the above circle will have an area of:

A

= π

( 3 )

2

22

7

( 9 )

=

2

28

7 in

2

When talking about circles, the word circumference replaces the word perimeter

XIX

Solving Inequalities

Law 12

The Addition Law of Inequality (

Law of ineq)

∀ a, b, c,

R

If a < b then a + c < b + c

Law 13

The Multiplication Law of Inequality (

Law of ineq)

∀ a, b, c,

R

If a < b then ac < bc iff c > 0 but

If a < b then ac > bc iff c < 0

XIX Solving Inequalities

(continued)

Ex 1) 1

3

+ c

5

> −

3

2

1

3

1

3

1

3

+ c

5

1

3

+ c

5

> −

3

2

1

3

> −

3

2

3

3

1

3

2

2

0

+

0

+ c

5 c

5

>

>

9

6

9

6

2

2

6 c

5

5

1

⋅ c

5

> −

11

6

> −

11

6

5

1

1

⋅ c

> −

55

6 c

> −

9

1

6

Given

Law of ineq

Assoc |

I.D. Twice

Inv | Arith

Arith

I.D. | Arith

Law of ineq

Inv | Arith

I.D. | Arith

Now that we have isolated the variable, we must show the solution for the inequality in one of 3 ways. We can either graph it, or write it in one of two types of solution sets.

Solution sets can either be written in

Set Builder Notation

(SBN), or Interval

Notation (IN)

-10 -5 0 5 10

(

Set Builder Notation c | c

> −

9

1

6

Interval Notation

9

1

6

,

Whenever using Set

Builder notation, you must put braces { } on the outside of the set to indicate that this is the solution set.

When solving an inequality, it is important to note that when multiplying by a negative number, the direction of the inequality sign must be reversed.

XIX

Solving Inequalities,

(Continued)

When graphing or writing the solution set in interval notation, if the end point is known, you must use a bracket.

Use a parenthesis to indicate an unspecifiable end point.

When solving inequalities, it is also important to take note that 2

3 y

=

2

3 y

2

XIX Solving Inequalities

(continued)

Ex 2)

3

4 x

+ 

3

4 x

5

6

+

5

6

5

6

1

2

1

2

5

6

Note that we multiplied by a negative number so the inequality changed direction.

(Mult. Law of inequality)

4

3

⋅ −

3

4 x

≥ −

4

3

1

2

5

6

 x

≥ −

4

3

1

2

5

6

 x

4

6

+

20

18

Here we use the distributive law of multiplication over addition

In order to add these two fractions together, we find an LCD using the

Jealousy Method (VI) x

2

3

+

10

9 x x

3

3

2

3

6

+

10

+

9

10

3

3 x

1

7

9

1 7

9

[

-2 -1 0 1 2

Solution Sets

IN SBN

 1

7

9

,

 x | x

1

7

9

XX Chains of Inequalities

(Compound inequalities)

Ex 1)

When two inequalities are combined to show that an expression lies between two fixed values, this is known as a

Compound Inequality.

2

+

3

5 x

<

1

2

+

3

1

5 x

<

3

1

2

1

5

1

1

5

5 x

<

1

5

7

2

Compound

Inequalities must be solved from the middle

1

5

≤ x

<

7

10

The Solution can be verbalized as all of the x’s between one fifth and seven tenths.

IN



1

5

7

,

10

SBN x |

1

5

≤ x

<

7

10

0 ¼ ½ ¾ 1

[ )

1

5

7

10

XXI

Graphing Two Variable Linear Equations

a) Descartes (Inventor of the Cartesian Coordinate System)

All real Numbers can be graphed using the Cartesian Coordinate System

When plotting on these graphs, it is imperative to remember that x always comes first when writing the points

It is good practice to plot three points when you are first starting, simply to check your work, however, it is only necessary to plot two points.

XXI Graphing Two Variable Linear Equations

(Continued)

XXI Graphing Two Variable Linear Equations

(Continued) b) Go to Work

W hen trying to graph an equation, then the

Point Plotting Method is a good method to use. This method is a quick and easy way to find where the x and yintercepts are located.

First a table, as shown in the previous slide, must be created, only instead of the complicated table shown earlier, the only table necessary to graph an equation like

2 x

+

3 y

=

1 looks like this:

When substituting a number for x or y , always use 0, as it will save endless time and energy.

x

0 y

?

?

0

So if we substitute zero for x to find y , our equation will look something like this

2 ( 0 )

+

3 y

=

1

3

3 y y

=

=

1

1

3

3

So now we can fill in the ? For y in the above table

And if we substitute zero for y to find x , our equation will look something like this

2 x

+

3 ( 0 )

=

1

2 x

2 x

=

1

=

2

1

2

XXII

Graphing

Single

Variable Equations in Two Dimensions

Ex 1) Graph

When x is the variable, the line is vertical.

x y

3½ 0

3½ 1

3½ 2

3½ 3

3½ 4

3½ 5

3½ 6

XXIII

In order to use the Slope Method we must first change the equation from General Form, into Slope Intercept Form y = mx + b

Where m = slope b = y -intercept

To make this change, we must get y alone in the equation.

Ex 1)

Now that we have the slope intercept form, we know that the y -intercept is located at and we know that the slope is positive so now we can graph it as shown:

XXIII

Graphing Two Variable Equations using Slope Method

(Continued)

There are three key steps in graphing equations with the Slope Method.

1.

Get y alone, or change the equation from General Form to Slope Intercept Form

2.

Pick off, and spot the yintercept. It is important to remember to do this step before the next step.

3.

Plot the rise over run, or the slope. As shown in the previous slide, the slope of the equation is m 3

7 of three parallel to the y -axis, we will run positive seven parallel to the x -axis.

The slope of a line passing through points ( x

1 is

, y

1

) and ( x

2

, y

2

) m =

Vertical Change

Horizontal Change

=

Rise

Run

=

Change in y

Change in x

= y x

1

1

− y x

2

2 if x

1

≠ x

2

XXIV Nuances

There are several facts that must be observed when working with single variable equations. It must be remembered that a horizontal line has a slope of zero, while a vertical line has an undefined (infinite) slope. A good way to remember this is to remember that when solving for y in a single variable equation (like Ex 2 in XXII), the slope will be zero because y = mx + b becomes y = (0) x + b which reduces to y = b .

However, when solving for x in a single variable equation, the slope will be undefined

(infinity). This is because in any vertical line, no matter what the rise is, the run is always 0. Division by 0 is undefined (rise/0 = ∞ ), hence infinite, since there are an infinite number of 0’s in any number.

Parallel lines have the same slope, and can be symbolized



Perpendicular lines will always have slopes that are “negative reciprocals” of each other.

The symbol for perpendicular lines is ⊥ . All horizontal lines are ⊥ to all vertical lines x

− y Find the slope of a line

⊥ to this line

4 y

4

=

3 x

4

+ y

=

3

4 x

7

4

7

∴ is a symbol that means therefore

4

4

∴ a line that is ⊥ to this line would have a slope of

3

XXV

Find Equations Given Facts

(Analytical Geometry)

Step 1

Draw a picture (DAP)

Ex 1) If a line goes thru (-2,4) and has a slope of -3, find the equation of the line in both GF & SIF

Step 1) Draw A Picture

Step 2

Write the SIF formula: y = mx +b

(-2,4)

(-1,1)

Step 3

Plug in known “ m ” value and any known ( x,y ) point.

Step 4

Solve for “ b ”

Step 5

Insert m and b values into y = mx + b to get answer in SIF. For GF, clear any fractions and move the x term to the far left side of the equation.

The x term must also be positive.

XXV

Find Equations Given Facts

(Continued)

Step 2) Write y = mx + b

Step 3) Plug in Known Facts

This is the most critical part of the process, because extreme care must be taken to insure that all facts are plugged in at the proper place, or the equation will be wrong. We know slope = -3 and it has the point (-2,4) y = -3 x + b

4 = -3(-2) + b

Step 4) Solve for b.

4 = 6 + b

-2 = b

Step 5) Insert m and b values into y = mx + b

Now that the y -intercept has been found, all the information is known to write the equation in SIF y = -3 x – 2 which can be changed to 3 x + y = -2 to obtain General Form (GF)

XXV

Find Equations Given Facts

(Continued)

Ex 2) Find the equation of a line parallel to 3 x – 4 y = -1 that goes thru (-2,-1)

Step 1)

DAP

XXV

Find Equations Given Facts

(Continued)

Step 2)

Write y

= mx

+ b

Step 3)

Plug in known facts (slope and point (-2,-1))

1

=

3

4

(

2 )

+ b

Step 4) Solve for b

1

= −

3

2

+ b

3

2

1

= b

1

2

= b

Step 5) Now we have both slope and y-intercept.

∴ y

=

3

4 x

+

1

2

XXV

Find Equations Given Facts

(Continued)

Step 5) continued

SIF is: y

=

3

4 x

+

1

2

To get the GF, we must put the x on the other side in order to arrange the equation into general form ax

+ by

= c

3

Or

− x

+ y

=

1

4 2

But we cannot have any fractions or a negative in front of x , so we must multiply the equation by the LCD of all the denominators and by -1 in order to simplify the equation into GF

Multiply by (4)(-1) = -4

4

3

4 x

+ y

= −

4

1

2

3 x

4 y

= −

2

Voila!

XXV

Find Equations Given Facts

(Continued)

Ex 3) Find the equation of a line that passes thru the two given points (-3,0) & (3,1)

Step 1) DAP

XXV

Find Equations Given Facts

(Continued)

Write

Step 2) y

= mx

+ b

Step 3)

Plug in known facts, 1/6 & point (3,1) y

=

1

6 x

+ b

Step 4)

Simplify and return “ b ” to SIF

1

=

1

6

3

+ b

1

=

1

2

+ b

1

1

2

= b

1

2

= b y

=

1

6 x

+

1

2 Now see if you can convert to GF!!

XXVI Graphing Two Variable 2-D Inequalities

Step 1: Graph the equation as if it is an equality. Use either

Slope Method, or Point plotting method.

Step 2: Use a solid line if it is ≤ , or ≥ , and use a dotted line if <, or >.

Step 3: Test a point. The easiest and best point is (0,0). If the point is false, shade the other side of the line.

SLOPE METHOD

Ex1) 2x – 3y < -1

POINT PLOTTING METHOD

-3y < -2x – 1

For X

2x – 3(0) < -1

For Y

2(0) – 3y < -1

-3y < -2x – 1

-3 -3 y < 2x + 1

3

2x <-1

2 2 x < -½

-3y < -1

3 3 y < ⅓ x

0

-½ y

⅓ o

XXVI Graphing Two Variable 2-D Inequalities

(Continued)

XXVI

Graphing Two Variable 2-D Inequalities

(Continued)

Ex2) -2x + 8 > 5

-2x > -3

2 2

-x > -3

2 x < 3

2

XXVII

Function Notation Introduced f(x) means a function (an algebraic expression) evaluated at whatever x is

Or

A statement where the only variable is x

Or

Y is a statement in terms

A function is a set of ordered pairs (a relation) in which to each first component, there corresponds exactly one second component. Therefore, if to each value of x in a given domain, there is assigned exactly one value of y in the range, then y is said to be a function of x.

The notation y = f(x) denotes that the variable y is a function of x.

F(x) = f of x not f ✖ x

XXVII

Function Notation Introduced

(Continued)

Ex1) f(x) = 2x – 3 find f(-1) f(-1) = 2(-1) – 3 f(-1) = -2 – 3 f(-1) = -5

Find f(2) f(2) = 2(2) – 3 f(2) = 4 – 3 f(2) = 1

Ex1) Graph a) 2x – 3y = 8 b) -x + y = -7 a)

X

0

4

Y

-8

3

0 b)

X

0

7

Y

-7

0

XXVIII

Systems

(Bunches of Equations)

XXIX

Two Methods of Solving Systems a) Substitution Method

1) Solve either equation for either variable.

2) Force result (a.k.a. THE BLOB) into the other equation

3) Solve the resulting single variable equation.

4) Put the result into the BLOB to get the other variable value.

Ex1) a) 2x – 3y = 8 b) –x + y = -7

Step 1: b) y = x – 7

Step 2: a) 2x – 3(x – 7) = 8

As equation b) is already solved for y, that will be the BLOB.

Step 3

XXIX

Two Methods of Solving Systems

(Continued) a) 2x – 3(x – 7) = 8

2x – 3x + 21 = 8

The substitution method is best used when

∃∃∃∃ positive 1 on at least one variable.

( ∃∃∃∃ means there exists)

-x + 21 – 21 = 8 – 21

-x = -13 x = 13

Step 4) Now that we have solved for x, we can force it into the BLOB

∴ y = 13 – 7 y = 6

This point (13,6) is is actually where equations a & b intersect, and is the

Solution Set

(13,6)

.

XXIX

Two Methods of Solving Systems

(Continued)

Ex2) a) x + y = 1

4 4 b) y + 11 = x

2 20 10

Because the y is a positive 1, the substitution method should be used, with equation a used for the BLOB.

However, before this equations can be solved, all fractions must be cleared

Eq. a) 4 ( + y = )

1 4 4

Step 1) x + 4y – 4y = 1 – 4y x = -4y + 1 BLOB

Eq. b) 20 ( + = )

Step 2) 10y + 11 = 2(1 – 4y)

Step 3) 10y + 11 = 2 – 8y

10y +8y + 11 = 2 – 8y + 8y a) x + 4y = 1

18y + 11 – 11 = 2 - 11 b) 10y + 11 = 2x

18y = -9

18 18

Now these equations can be solved using the substitution method y = -½

Step 4) Put answer into

BLOB x = 1 – 4(-½) x = 3

The solution set for equations a & b is:

(3, -½)

XXIX

Two Methods of Solving Systems

(Continued) b) Addition Method

(a.k.a. Elimination Method)

Step 1) Be sure x’s, y’s, and constants

(no variable) are lined up.

it

Step 2) Multiply through equation a or b, or both, by whatever takes so that when added, either x or y will cancel.

Step 3) Solve the resulting single variable equation.

Step 4) Use that result in either equation to get the value of the other variable.

XXIX

Two Methods of Solving Systems

(Continued)

Ex1) Eq a) 2x – 3y = 8

Eq b) 5x + 2y = -7

Step 2: 2(2x – 3y = 8)

3(5x + 2y = -7)

2( ) – 3y = 8

19

_ 10 – 3y = 8

19

-3y = + 8 19

19

-3y = 10 + 152

19

_ 1

3

(-3y) = ( )

19 3 / y =

19

19x = -5

19 19 x = _ 5

19

XXX

Use Systems to Solve Word Problems

Ex1) Alaska: Most of the 1,422 mile-long Alaskan Highway is actually in Canada.

Find the length of the highway that is in Canada if it is known that the difference in lengths is 1,020 miles.

a)x + y = 1,422 b) x – y = 1,020 b) x = y + 1,020 BLOB a)(y + 1,020) + y = 1,422

2y + 1,020 – 1,020 = 1422 – 1020

2y = 402

2 2

Y = 201 miles of the highway are in the U.S.

∴ x + 201 – 201 = 1422 - 201

Or

X = 1221 miles are in Canada

XXX

Use Systems to Solve Word Problems

(Continued)

Ex 2) Pension Funds: A state employees’ pension fund invested a total of one million dollars into two accounts that earned 3.5% and 4.5% annual interest. At the end of the year, the total interest earned from the two investments was $39,000. How much was invested at each rate?

a) x + y = 1 million

( x +

100 y = 39,000)1000

Y = -x + 1 million BLOB

35x + 45(-x + 1 million) = 39 million a) 600,000 + y = 1,000,000

-10x = -6 million

10 10

600,000 – 600,000 + y = 1,000,000 – 600,000

-x = - $600,000 y = $400,000

X = $600,000

XXXI

Geometry Word Problems

Facts

a) Angles of a triangle add up to 180 ° b) Right angles are 90 ° c) A whole circle is 360 ° d) Quadrantal angles are 90 ° , 180 ° , 270 ° , 360 ° , 450 ° , etc.

e) Supplementary angles add up to 180 ° f) Complimentary angles add up to 90 °

Ex1) Two angles are supplementary. The measure of one angle is 20 less than 19 times the measure of the other. Find the measure of each angle.

a) x + y = 180 b) x – 19y – 20

(19y – 20) + y = 180

20y = 200

20 20 y = 10 therefore x = 170

XXXII

Mixture Word Problems

Ex1) Mouthwash a pharmacist has a mouthwash solution that is 6% ethanol acohol and another that is 18% ethanol alcohol. How many millimeters of each

XXXIII

Distance Word Problems

Distance = Rate × Time

Ex1) The jet stream is a strong wind current that flows across the United States. Flying with the jet stream a plane flew 3000 miles in five hours. Flying against the same wind, the trip took six hours. Find the speed of the plane in still air, and the speed of the wind. a)3000 = r(5) b) 3000 = r(6)

R = 600 r = 500

This is not correct.

The different rates must be distinguished a) 3000 = (r p

+ r w

)5 b) 3000 = (r p

– r w

)6

5r p

+ 5r w

= 6r p

– 6r w

11r w

= 1r p

BLOB a) 3000 = (11r w

+ r w

)5

3000 = 60r w

60 60 r w

= 50mph ∴ r p

= 11(50) or 550mph

XXXIV

Graphing Systems of Linear Inequalities in Two Dimensions

(see XXVI)

Ex1) a) 2x – 3y ≤ 12 b) 3x + 5y ≥ 15

X

0

6

Equation A

Y

-4

0

PPM

Equation B

X

0

5

Y

3

0

The crosshatched yellow region is the solution set

.

XXXIV

Graphing Systems of Linear Inequalities in Two Dimensions

(Continued)

Ex2) a) 2x + y = 2 b) y = x c) x = 0

The yellow shaded area is the

Solution Set.

XXXV

Laws of Exponents

A) In multiplication of like bases, add the exponents and write the base just once.

Ex1) x 2 × x 3 = x 2+3 or x 5

Ex2) x 3x – 4y × x 5 – 2x + 6y x 3x -4y + 5 – 2x

A) In division of like bases, write the base just once then subtract the exponents (usually top from bottom).

B) In raising a power inside to a power outside, write the base just once and multiply the exponents.

C) In taking roots (radicals), divide the index of the radical (the number in the crotch) into the exponent of the base.

XXXVI

Exponent Examples

Ex 1) 3 4 * 3 6 = 3 10 (exponential form)

Ex 2) 10 4 =

10 4 – 2 or 10 2 = 100 (expanded form)

10 2

Ex 3) (m + 8) 20

(m + 8)

=

(m + 8) 20 – 1c = (m + 8) 19

Ex 4) x 4p * y 2x x p * y -3x

= x 4p – p * y 2x – (-3x) = x 3p * y 5x

Ex 5) x 3y (x -3 * y 4 + x 2y ) = x 3y – 3 + y 4 + x 5y

Ex 6) (s 3 t 3 ) 4

(st) 2

= s 12 t 12 = s 12 – 2 t 12 – 2 = s 10 t 10 = (st) 10 s 2 t 2

XXXVII

Expansions on the Schema

Ex1) 3x 2 y – xy 2 + 4xy 2 – 5x 2 y

-2x 2 y + 3xy 2

Ex 2) x 2 y(3x 2 y – 4xy 2 ) Contrast example

3x 4 y 2 – 4x 3 y 3

Operation Exponent

+ CLT

-

×

÷

CLT

+

Rp

Tr

-

×

÷

Corollaries to the quotient rule.

Ex 1) When exponents are the same x 4 – x 4 then x 4 – 4 = x 0 = 1

This is true, because anything divided by itself will result in one.

XXXVII

Expansions on the Schema

(Continued)

Corollaries to the quotient rule

Ex 2) When the exponent on bottom is greater than the exponent on top

X 4 = x 4 – 12 = x -8 = 1

X 12 x 8

This rule is known as the

Negative exponent corollary and can be written as a -n = 1 a n

This might look a little unusual, but from the definition of exponents in algebra, the exact same problem could be written xxxx _ xxxxxxxxxxxx

Once everything has been canceled, a one will be left on top while eight x’s will be left on bottom

Or

1 x 8

XXXVIII

Example of Zero & Negative Exponent Corollaries

Ex 1) x

4

-2

-6 y 0 z

5 -2 ( ) x -8 y 12 z -10 x 4 y 0 z 10 x -8 – 4 y 12 - 0 z -10 – 10 x -12 y 12 z -20

Steps

1)Use the raising to a power rule

2)Use the quotient rule

3)Use the negative exponent rule y 12 x 12 z 20

XXXIX

Scientific Notation

a) LARGE numbers are characterized with positive exponents

Ex 1) 93,000,000======= 9.3 × 10 7

Standard notation Scientific Notation b) SMALL numbers are characterized with negative exponents

Ex 1) .000032 ======== 3.2 × 10 -5

Standard Notation Scientific Notation

Ex 2) 6 × 10 -8 ======== .00000006

Scientific Notation Standard Notation c) Operating in Scientific notation

1) Multiplication problems

Ex1) 300,000(.00042)

(3 × 10 5 )(4.2 × 10 -4 )

XXXIX

Scientific Notation

(Continued) c) Operating in Scientific notation

Ex 1) Continued

(3 × 4.2)(10 5 × 10 -4 )

12.6 × 10 5 – 4

12.6 × 10 1

126 Standard Notation

1.26 × 10 2 Scientific Notation

2) Division Problems

Ex 1) 48,000

.0000008

(4.8 × 10 4 )

(8 × 10 -7 )

If asked to put the answer into scientific notation, only this answer is correct

.6 × 10 4 – (-7)

Or

.6 × 10 11

Or

6 × 10 10 Scientific Notation

XXXIX

Scientific Notation

(Continued)

3) Raising to a power problems

Ex 1) (.000004) -3

(4 × 10 -6 ) -3

4 -3 × 10 18

1 × 10 18

4 3

1 or 64

× 10 18

.015625

× 10 18 Or 1.5625 × 10 16 Scientific Notation

4) A mixture of Operations

(.000008)(320,000)

.00024

1.06 ×

Or

10666.6

10 4

Once the problem has been completed, click the mouse for the answer

XL

Operating With Polynomials

a) Monomials – One term

Ex 1) -3x 2 y b) Binomials – Two terms

Ex 2) 3x 2 y – 4xy 3 c) Trinomials – Three terms

Ex 3) 2x 2 – 4x + 5 d) Four or more terms are called polynomials.

e) Addition and subtraction of polynomials

Ex 1) (2x 2 – 3x) – (4x 3 – 3x 2 + 8)

2x 2 – 3x – 4x 3 + 3x 2 – 8

-4x 3 + 5x 2 – 3x – 8

It is important to remember that the highest power should always be written first

XL

Operating With Polynomials

(Continued) f) Evaluating polynomials (see XII)

- x 2 – ( 10x 2 – 3x) – 4( x 2 – 5x)

3 5 3

2x 2

3

– 8x + – 8x 2 + 20x

5 3

34x 2 112x

3 5

-170x 2 + 336x

15 Evaluate when x = -2

- 170(-2) 2 + 336(-2)

15

==========

15

-1352

15

1) x -3 x 4x + 2

2) x -4 x -3 + x

3) (x -3x – 4 ) -5

4) a b a b + 1

5) a -3 b -3 + 4x

6) a 2x – 4 a 3x + 1

7) a 3b – 2 a 2 + 4b

8) (a 3b – 4 ) -2x

9) x -2 – x -1

10) i -x – 2i -1

XLI

Review for Test VII

XLII

Multiplication of Polynomials

a) Monomial multiplication

Ex 1) -3x 2 (2x – 4)

12x 2 – 6x 3 b) Binomial multiplication

Ex 2) -2x 3 y 2 (5x 2 – y

-10x 5

4 y

)

6

Ex 1) (2x – 3y)(2x 2 – 3x + 4)

4x 3 – 6x 2 + 8x – 6x 2 y + 9xy – 12y c) Trinomial Multiplication will yield twevle terms, unless it is possible to CLT d) Two very critical special cases

1) Product of conjugates ( difference of squares) expressed as same two binomials with different signs

XLII

Multiplication of Polynomials

(Continued)

Ex 2) (2x 2 y 3 – 3xy 2 )(2x 2 y 3 + 3xy 2 ) Ex 1) (2x – 3y)(2x + 3y)

4x 2 – 9y 2 4x 4 y 6 – 9x 2 y 4

2)Squaring of a binomial

Ex 1) (2x 2 y – 3xy 2 ) 2

Step 1) 4x 4 y 2

Step 2) 2x 2 y × 3xy 2

-12x 3 y 3

Step 3)

Step 4)

9x 2 y 4

4x 4 y 2 – 12x 3 y 3 + 9x 2 y 4

The rules for squaring a binomial

1)Square the first term

2)Twice the cross product (TCP) a) Do the sign first b) Do the numbers 2 nd c) Do x’s next d) Do y’s e) Twice the answer

3)Square the 2 nd term

4)Combine the three answers for the final answer.

XLII

Multiplication of Polynomials

(Continued)

E) Cubes and higher powers of a binomial

Ex 1) (x – 2y) 3 or (x – 2y) (x – 2y) (x – 2y)

Treat as a square 1 st

(x 2 – 4xy + 4y 2 )(x – 2y) x 3 – 4x 2 y + 4xy 2 – 2x 2 y +8xy 2 – 8y 3

Or

X 3 – 6x 2 y + 12xy 2 – 8y 3

XLII

Multiplication of Polynomials

(Continued) f) A mixture of types

Ex 1) -3(x 2 – .2y) 2 – 2x(x – 2 y 2 )(x + y 2 )

3

2

3

-3(x 4 - .4x

2 y + .04)2x(x 2 4 – y 4 )

9

-3x 4 + 1.2x

2 y – .16y

2 – 2x 3 8

+ xy 4

9

XLIII

Division of Polynomials

a) Division of a polynomial by a monomial

Ex 1) 2x 2 – 3xy + 4x 2 y 2

24x 3 y 2

2x 2 _ 3xy

+

4x 2 y 2

24x 3 y 2 24x 3 y 2 24x 3 y 2

1 _ 1

+

1

12xy 2 8x 2 y 6x

Ex 2) 3x -4 – 2x 5

6x 7

3x -4 _ 2x 5

6x 7 6x 7 x -11 _ x -2 or 1 _ 1

2 3 2x 11 3x 2

XLIII

Division of Polynomials

(Continued) b) Division of a polynomial by a binomial

Ex 1) x 3 – 8 x – 2 x 2 + 2x + 4 x – 2)x 2 + 0x 2 + 0x 1 – 8

_ x 3 – 2x 2

2x 2 – 0x 1

2x 2 + 4x 1

4x – 8

-4x + 8

0

Rules

0) Ensure that the problem is arranged in descending (or ascending) order, with all powers mentioned

1)Divide the first term into the first term.

2)Multiply that result by both numbers of the divisor.

3)Draw a line, change signs and add

4)Bring down next term and repeat steps

1,2,3

XLIV

Five Types of Factoring

a) Intro – In Arithmetic

Trivial factors are 1 and the number itself. In this case the trivial factors would be 1 & 15.

b) Common Monomial Factoring (Distributive Law Backwards)

Ex 1) 6x 2 y

2x

3

2

– 8x y 2

4 y 2 + 10x

(3y – 4x 2

3 y 3

+ 5xy)

Find a common factor and write just once.

In this case 2x 2 y 2 is the common factor.

c) Grouping (Multiple [usually three times] use of common monomial type)

Ex 1) 12ab – 4ac + 3bd – cd

4a(3b – c) + d(3b – c)

BLOB BLOB

(3b – c)(4a + d)

XLIV

Five Types of Factoring

(Continued)

Ex 2) 4abc + 4ac 2 – 2bc – 2c 2

2c(2ab + 2ac – b – c)

2c(2a[b + c] – [b + c])

2c([b + c][2a – 1])

In order to check the answer use the FOIL

(first, outside, inside, last) method to get back to four terms d) Trinomial factoring

Ex 1) 8x 2 – 2x – 15

Example Continued on next slide

d) Trinomial Factoring

Ex 1) 8x 2 – 2x – 15

XLIV

Five Types of Factoring

(Continued)

Step 2)

Step 3)

Step 4)

Step 5)

Step 6)

(2x ?)(4x ? )

8x 2 – 2x – 15

(2x 3)(4x 5)

12x

10x

(2x 3)(4x 5)

- 12x

+ 10x

(2x – 3)(4x + 5)

Rules

1)Pick two numbers that will multiply together to get 1 st term, and usually (probability favors this) use the two closest to each other.

2)Pick two numbers that multiply together to get the last term.

3)Multiply the inners.

4)Multiply the outers.

5)Pick signs to give the middle term.

6)Upper sign to the left, lower sign to the right.

7)Check to be sure last terms multiply to give the last term.

XLIV

Five Types of Factoring

(Continued)

Ex 2) 16r – 40r 2 + 25r 3 r(16 – 40r +25r 2 ) r(4 – 5r)(4 – 5r)

- 20r

- 20r r(4 – 5r) 2

Ex 3) 6s 5 – 26s 4 – 20s 3

2s 3 (3s 2 – 13s – 10)

2s 3 (3s ? 2s)(s ? 5)

2s

15s

2s 3 (3s + 2)(s – 5)

Ex 4) 6x 2 + x – 12

(2x )(3x )

(2x 3)(3x 4)

+ 9x

- 8x

(2x + 3)(3x – 4)

XLIV

Five Types of Factoring

(Continued)

Mac’s Rule

Never put like factors into the same parenthesis.

Ex 1) (2x + 3) is okay

(3x – 3) is not okay e)Difference of Squares (Product of conjugates)

Ex 1) 4x 2 – 81

(2x + 9)(2x – 9)

As defined earlier in these notes, the word difference can be translated mathematically into subtraction.

XLIV

Five Types of Factoring

(Continued) e) Difference of Squares

Ex 2) (16x 12 – 121y 6 )

(4x 2 + 11y 3 )(4x 2 – 11y 3 )

Any even power is a square

Ex 3) 12x 6 – 3y 2 z 4

3(4x 6 – y 2 z 4 )

3(2x 3 +yz 2 )(2x 3 – yz 2 )

Don’t be fooled by difference of squares that are masked with a simple monomial as shown in example 3

XLIV

Five Types of Factoring

(Continued)

( Cube

Root of

As problem

Rules f) Factoring of Cubes

A B different

)(A

2

Sign from original

AB + B

2

) problem 1 st term

Same

Sign

Cube

Root of

2 nd term

Ex 1) 8x 3 + 1

(2x + 1)(4x 2 -2x + 1)

Ex 2) (x 3 y 6 – 27z 9 )

(xy 2 – 3z 3 )(x 2 y 4 + 3xy 2 z 3 + 9z 6 )

XLV

Review of Types

1) Common Monomial – any number of terms

2) Difference of Squares – two terms

3) Trinomial – three terms

4) Grouping – four terms

5) Cubes – two terms

XLVI

Uses of Algebraic Factoring a) To Solve factorable equations of degrees (powers) greater than one.

Ex 1) 2x 2 – 8 = 0

1 st degree equations are called linear equations.

2 nd degree equations are called quadratic equations.

3 rd degree equations are called cubic equations

2(x 2 – 4) = 0

4 th degree equations are known as quartic equations.

5 th degree equations are called quintic equations.

2(x + 2)(x – 2) = 0

SS { x| x = + 2} or

SS {x| x = 2, x = -2}

An Equation will yield as many answers as the highest degree of the equation. In this case, the highest power is two, and that is how many answers will be in the solution set

XLVI

Uses of Algebraic Factoring

(Continued)

Ex 2) 2x 3 – 3x 2 – 2x + 3 = 0 x 2 (2x -3) – (2x – 3)

(x 2 – 1)(2x – 3) = 0

(x – 1)(x + 1)(2x – 3) = 0

2x – 3 = 0 x – 1 = 0 x + 1 = 0

2x = 3

2 2 x = 1 x = -1 x = 3 SS {x| x = + 1, x = }

2

2

Notice that this is a cubic equation, which means it will yield three answers.

XLVI

Uses of Algebraic Factoring

(Continued)

Ex 3) x 4 – 13x 2 + 36 = 0

(x 2 – 4)(x 2 – 9) = 0

- 4x 2

- 9x 2

(x – 2)(x + 2)(x – 3)(x + 3) = 0 x – 2 = 0 x = 2 x + 2 = 0 x = -2 x – 3 = 0 x + 3 = 0 x = 3 x = -3

SS { x| x = + 2, x = + 3}

XLVI

Uses of Algebraic Factoring

(Continued) b) To Reduce Algebraic Fractions

Ex 1) x 2 – 2x + 1

3x 2 – 3

Rules

1)Prime factorize tops and bottoms.

1)Cancel Like Factors.

(x – 1)(x – 1)

3(x – 1)(x + 1)

(x – 1)

3(x + 1)

Ex 2)

XLVI

Uses of Algebraic Factoring

(Continued)

4 – b b 2 – 5b + 4

4 – b

(b – 4)(b – 1)

-1 _

(b – 1) b – 4 ≠ 4 – b

Opposites will always yield -1

Just as

6

-6

Will yield -1

Or

1 _

1 – b

XLVI

Uses of Algebraic Factoring

(Continued) c) Multiplying fractions

Ex 1)

Rules

1)Prime factorize tops and bottoms.

11m .

14 _

21 55m 3

2)Cancel any top with a like bottom.

3)Move left to right when solving.

11m

.

7 × 2 _

7 × 3 11 × 5 × m × m × m

2_

15m 2

XLVI

Uses of Algebraic Factoring

(Continued)

Ex 2) p 2 – p – 6 2p 2 – 5p – 3

3p – 9 p 2 – 3p

(p + 2)(p – 3) (2p + 1)(p – 3)

3(p – 3) p(p – 3)

(p + 2)(2p + 1)

3p

XLVI

Uses of Algebraic Factoring

(Continued) d) Division of Fractions

Ex 1) x 2 – x – 6 _

÷ x 2 – 25 _

2x 2 + 9x + 10 2x 2 + 15x + 25

÷ x 2 – x – 6 _

2x 2 + 9x + 10

2x 2 + 15x + 25 _ x 2 – 25

(x + 2)(x – 3)

(2x + 5)(x + 2)

÷

(2x + 5)(x + 5)

(x + 5)(x – 5)

Rules

1)Invert back or bottom fraction.

2)Prime factorize tops and bottoms.

3)Cancel any top with a like bottom.

4)Move left to right when solving.

x – 3 x – 5

XLVI

Uses of Algebraic Factoring

(Continued)

Ex 2) 6x 3 – 48y 6

8(x – 2y 2 )

6(x 3 – 8y 6 )

8(x – 2y 2 )

6(x – 2y 2 )(x 2 +2xy 2 + 4y 4 )

8(x – 2y 2 )

3(x 2 + 2xy 2 + 4y 4 )

4

XLVI

Uses of Algebraic Factoring

(Continued) e) Addition and Subtraction of Fractions

Rules to get LCD

Ex 1)

3x 2

2x _

– 27

+

5x 2 x – 1 _

+ 11x – 12

1)Prime factorize

Denominator only

2)Get Jealous

2x _

+ x – 1 _

3(x + 3)(x – 3) (5x – 4)(x + 3)

GET JEALOUS

(5x – 4)(2x) + 3(x – 3)(x – 1)

3(5x – 4)(x + 3)(x – 3)

13x 2 – 20x + 9

3(5x – 4)(x + 3)(x – 3)

Download