Algebra II 1.4 Simplifying Algebraic Expressions PP

advertisement
1-4
1-4 Simplifying
SimplifyingAlgebraic
AlgebraicExpressions
Expressions
Warm Up
Lesson Presentation
Lesson Quiz
Holt
Algebra
Holt
Algebra
22
1-4 Simplifying Algebraic Expressions
Do Now
List words that indicate each operation.
1. addition
2. multiplication
Evaluate each expression.
3. 3x for x = 2
4. 5x – 4 – 3x for x = 7
Simplify each expression.
5. 3(2x)
6. 4(x + y)
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Objective
TSW simplify and evaluate algebraic
expressions.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
There are three different ways in which a
basketball player can score points during a game.
There are 1-point free throws, 2-point field goals,
and 3-point field goals. An algebraic expression
can represent the total points scored during a
game.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
To translate a real-world situation into an algebraic
expression, you must first determine the action being
described. Then choose the operation that is indicated
by the type of action and the context clues.
Action
Combine
Combine equal
groups
Separate
Separate into
equal groups
Holt Algebra 2
Operation
Add
Possible Context Clues
How many total?
Multiply
How many altogether?
Subtract
How many more? How
many remaining?
Divide
How many in each group?
1-4 Simplifying Algebraic Expressions
Example 1: Translating Words into Algebraic
Expressions
Write an algebraic expression to represent
each situation.
A. the number of apples in a basket
of 12 after n more are added
B. the number of days it will take to
walk 100 miles if you walk M miles
per day
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 1 continued
Write an algebraic expression to represent
each situation.
c. Lucy’s age y years after her 18th birthday
d. the number of seconds in h hours
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
To evaluate an algebraic expression, substitute a
number for each variable and simplify by using
the order of operations. One way to remember the
order of operations is by using the mnemonic
PEMDAS.
Order of Operations
1.
2.
3.
4.
Parentheses and grouping symbols.
Exponents.
Multiply and Divide from left to right.
Add and Subtract from left to right.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 2: Evaluating Algebraic Expressions
Evaluate the expression for the given values
of the variables.
2x – xy + 4y for x = 5 and y = 2
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 3: Evaluating Algebraic Expressions
Evaluate the expression for the given values
of the variables.
q2 + 4qr – r2 for r = 3 and q = 7
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 4
Evaluate x2y – xy2 + 3y for x = 2 and y = 5.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Recall that the terms of an algebraic expression
are separated by addition or subtraction
symbols. Like terms have the same variables
raised to the same exponents. Constant terms
are like terms that always have the same value.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
To simplify an algebraic expression, combine like
terms by adding or subtracting their coefficients.
Algebraic expressions are equivalent if they
contain exactly the same terms when simplified.
Remember!
Terms that are written without a coefficient have
an understood coefficient of 1.
x2 = 1x2
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 5: Simplifying Expressions
Simplify the expression.
3x2 + 2x – 3y + 4x2
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 6: Simplifying Expressions
Simplify the expression.
j(6k2 + 7k) + 9jk2 – 7jk
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 7
Simplify the expression –3(2x – xy + 3y) – 11xy.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 8: Application
Apples cost $2 per pound, and grapes cost
$3 per pound.
Write and simplify an expression for the total
cost if you buy 10 lb of apples and grapes
combined.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 9: Application
Apples cost $2 per pound, and grapes cost
$3 per pound.
What is the total cost if 2 lb of the 10 lb are
apples?
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 10
A travel agent is selling 100 discount packages.
He makes $50 for each Hawaii package and $80
for each Cancún package.
Write an expression to represent the total the
agent will make selling a combination of the
two packages.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 11
How much will he make if he sells 28
Hawaii packages?
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Example 12
Holly’s hybrid car gets 45 miles per gallon on the highway
and 25 miles per gallon in the city.
Write & simplify an expression for the total number of miles
she can drive if her fuel tank hold 15 gallons of gas.
Let h = # gallons used on the highway.
How many total miles can she drive on one tank of gas if she
used 5 gallons on the highway?
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Lesson Quiz: Part I
Write an algebraic expression to represent
each situation.
1. the number of cards in a 52-card deck after n
cards are dealt.
2. the number of days in W weeks
3. Evaluate: rq2 + 3qr + r2 for r = 5 and q = 2.
4. Simplify: 5h2 + 4k + 7h – 4h2.
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Lesson Quiz: Part II
Jake has only nickels and dimes in his
pocket.
5. Write and simplify an expression for the
total value if Jake has 20 coins.
6. How much does he have if he has 7 nickels?
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Lesson Quiz: Part I
Write an algebraic expression to represent
each situation.
1. the number of cards in a 52-card deck after n
cards are dealt. 52 – n
2. the number of days in W weeks 7W
3. Evaluate: rq2 + 3qr + r2 for r = 5 and q = 2. 75
4. Simplify: 5h2 + 4k + 7h – 4h2. h2 + 4k + 7h
Holt Algebra 2
1-4 Simplifying Algebraic Expressions
Lesson Quiz: Part II
Jake has only nickels and dimes in his
pocket.
5. Write and simplify an expression for the
total value if Jake has 20 coins.
Possible answer: $2 – ($0.05)N
6. How much does he have if he has 7 nickels?
$1.65
Holt Algebra 2
Download