+ Midterm Review + + Algebra Vocabulary Algebraic Expression- a math sentence involving a variable or unknown Variable- a symbol for a letter we don’t know yet Constant- a number on its own Coefficient- a number used to multiply a variable Operator- a symbol that shows an operation Like Terms- are terms whose variables (and their exponents) are the same. In other words, terms that are "like" each other. (Note: the coefficients can be different) Polynomial- an equation that has constants, variables and the exponents; NEVER DIVISION + Rules 1. You can only combine like terms 2. Signs (+/-) are attached to the coefficient and variable 3. - (-) = + 4. Positive + Positive = Positive 5. Positive + Negative = the sign of the larger digit 6. Negative – Negative = the sign of the larger number 7. Negative – Positive = negative 8. Positive x Positive = Positive 9. Positive x Negative = Negative 10. Negative x Negative = Positive 11. Positive Positive = Positive 12. Negative Negative = Positive 13. Negative Positive = Negative 14. Positive Negative = Negative + Operation Key Words Addition: sum, total, plus, in all, all together, and, increased by Subtraction: difference, less than, fewer, from, take away, are not, remain, how many more, exceed, remain Multiplication: times, each, in all, twice, product, factor, multiple, multiplied by Division: same, split, equal groups, separate, shared equally, distribute, cut up + Write an expression Identify the variable Look for key words Identify the operations Example: Take away 6 from 5 times of g Subtract and Multiply Answer: 5g-6 + Write an expression 5 more than quotient of x and 3 Addition and Division 5 + x/3 9 less than 8 times of y Subtraction and Multiplication 8y-9 Add 2 times of k and one-third Addition and Multiplication 2 + 1k/3 + Writing and Expression Product of 5 and y Quotient of 6 and a Take away 2 from q 4 is added to p 3 times of x One-half of q is added to 7 Two-third of the sum of 5 and m Six-fifth of h is subtracted from 3 5 less than quotient of w and 7 9 minus h + Adding Polynomials Line up like terms (this may involve re-arranging) 2x2 + 3xy+4 3x2+5xy+2 Add down the columns (Add like terms) 2x2 + 3xy+4 3x2+ 5xy +2 Note: the only aspect that changes is the coefficient Answer: 5x2+ 8xy + 6 + Adding Polynomials + Adding Polynomials + Subtracting Polynomials Line up like terms (this may involve re-arranging) 2x2 + 3xy+4 3x2+5xy+2 Multiply all terms in the second polynomial by -1 3x2+5xy+2 -3x2- 5xy -2 Add down the columns (Add like terms) 2x2 + 3xy +4 -3x2- 5xy -2 Note: the only aspect that changes is the coefficient Answer: -1x2-2xy + 2 + Subtracting Polynomials + Subtracting Polynomials + Distributive Property The distributive property lets you multiply a sum by multiplying each addend separately and then add the products. + Distributive Property 5 (3 +2) 2( 13 +7) 10 (5 +5) 25 (4+6) 50 (2+5) + Multiplying Exponents When multiplying variables with exponents, the coefficients are multiplied but the exponents are added together Example: (3x3) (10x4) (3 x 10) ( x3+4) 30x7 However, we can NOT simplify (x4)(y3), because the bases are different + Multiplying Exponents + Dividing Exponents Dividing exponents with same base For exponents with the same base, we subtract the exponents and leave the bases the same: a n / a m = a n-m Example: 26 / 23 = 26-3 = 23 = 2·2·2 = 8 + Dividing Exponents + Dividing Exponents Dividing variables with exponents For exponents with the same base, we can subtract the exponents: xn / xm = xn-m Example: x5 / x3 = (x·x·x·x·x) / (x·x·x) = x5-3 = x2 + Dividing Exponents with Coefficients and Variables Divide the coefficients Remember: top exponent minus bottom exponent. Remember: negative exponents can be written as a fraction. + Dividing Exponents with Coefficients and Variables The exponents are subtracted for the bases that are the SAME. The numbers in front, the coefficients, are divided. + Dividing Exponents with Coefficients and Variables Notice what happened to the bases with the same exponents – a0 which is equivalent to 1. + Distributive Property and Algebra Still distributing the number that is outside of the parenthesis to what is inside, except we can only combine like terms. 5x+10 15x2+30x 15x2+10x+30 + Distributive Property and Algebra + FOIL Method FOIL stands for: First - Multiply the first term in each set of parentheses Outer - Multiply the outer term in each set of parentheses Inner - Multiply the inner term in each set of parentheses Last - Multiply the last term in each set of parentheses + FOIL Simplify (3+7x) (6+2x) FIRST We'll start by multiplying the first term in each set of parentheses and then marking down the answer below the problem. + FOIL Simplify (3+7x) (6+2x) Outside Now we will multiply the outer terms and again mark down the answer below the problem. + FOIL Simplify (3+7x) (6+2x) Inside Now we will multiply the inner terms and again mark down the answer below the problem. + FOIL Simplify (3+7x) (6+2x) Last Now we will multiply the last terms and again mark down the answer below the problem. + FOIL Simplify (3+7x) (6+2x) Combine Like Terms We see that 6x + 42x = 48x, therefore our answer is: + FOIL Practice + What if we can’t use FOIL The FOIL Method cannot always be used to multiply two sets of parentheses. This is the case with the problem below. The second set of parentheses has 3 terms instead of two. For this, we will use another method. + Multiplying Polynomials First, split the problem by multiplying each term in the left polynomial by the entire second polynomial as shown below. + Multiplying Polynomials Then use the distributive property to simplify each. + Multiplying Polynomials Finally, combine like terms. + Multiplying Polynomials 1. Separate and rewrite 4a (6a2-a+2) + 2(6a2-a+2) 2. Use the Distributive Property (24a3-4a2+8a)+ (12a2-2a+4) 3. Combine Like Terms 24a3-8a2+6a+4 + Multiplying Polynomials + You Try + Addition X + 4 = 10 Get all variables on one side Get all constants on one side Find X To do this you subtract the constants X + 4 = 10 -4 -4 X+0=6 X= 6 + Practice X+ 29 = 50 25 + d = 13 36+y = 45 15 + v = 2 + Subtraction X - 4 = 10 Get all variables on one side Get all constants on one side Find X To do this you add the constants X - 4 = 10 +4 +4 X + 0 = 14 X= 14 + Practice X- 48 = 150 25 - d = 13 96-y = 45 v - 25 = 200 + Multiplication 4x = 20 Get all variables on one side Get all constants on one side Find X To do this you divide by the coefficient 4x = 20 4 4 x= 5 + Practice 3X = 150 -25d = 100 6y = 48 -5v = 200 -5x=-75 + Division x/4 =20 Get all variables on one side Get all constants on one side Find X To do this you multiply by the coefficient you are dividing by x/4 = 20 (4) x/4 = 20 (4) 4x/4= 80 X=80 + Division 100/x =20 Get all variables on one side Get all constants on one side Find X To do this you multiply by the variable you are dividing by and repeat the steps for multiplication 100/x = 20 (x) 100/x = 20 (x) 100x/x= 20 100=20x 20 20 X=5 + Practice x/33 = 11 -25/d = 5 y/6 = 48 500/v = 20 + Factoring Polynomials Reverse Foil Analyze each term in an expression and determine what was multiplied together • What multiplied together has a product of x2? (x) (x) • What multiplied together gives you a negative 15 but when added together results in positive 2? (5) (-3) = (x+5) (x-3) + Factoring Polynomials + Addition X + 4 < 10 Get all variables on one side Get all constants on one side Find X To do this you subtract the constants X + 4 < 10 -4 -4 X+0<6 X< 6 Rule applies if it is greater than, greater than or equal too, or less than and equal too + Practice X+ 29 < 50 25 + d < 13 36+y > 45 15 + v > 2 + Subtraction X – 4 < 10 Get all variables on one side Get all constants on one side Find X To do this you add the constants X – 4 < 10 +4 +4 X + 0 < 14 X< 14 + Subtraction If the variable is negative, you must divide by negative one and the sign of the inequality is changed 3 - x <5 -3 -3 -x < 2 -1 -1 X>-2 Rule applies if it is greater than, greater than or equal too, or less than and equal too + Practice X- 48 > 150 25 – d < 13 96-y < 45 v – 25 > 200 + Multiplication 4x < 20 Get all variables on one side Get all constants on one side Find X To do this you divide by the coefficient 4x < 20 4 4 x< 5 Rule applies if it is greater than, greater than or equal too, or less than and equal too + Multiplication -4x < 20 Get all variables on one side Get all constants on one side Since it is a negative coefficient we flip the sign Find X To do this you divide by the coefficient -4x < 20 -4 - 4 x> - 5 Rule applies if it is greater than, greater than or equal too, or less than and equal too + Practice 3X > 150 -25d < 100 6y < 48 -5v > 200 + Division x/4 <20 Get all variables on one side Get all constants on one side Find X To do this you multiply by the coefficient you are dividing by x/4 < 20 (4) x/4 < 20 (4) 4x/4< 80 X<80 + Division -3x/4 <20 Get all variables on one side Get all constants on one side Find X If the variable is attached to a negative coefficient you must switch the sign To do this you multiply by the coefficient you are dividing by -3x/4 < 20 (4/3)-3 x/4 < 20 (4/3) -12x/-12 < 80/-12 X> - 80/12 Rule applies if it is greater than, greater than or equal too, or less than and equal too + Division 100/x <20 Get all variables on one side Get all constants on one side Find X To do this you multiply by the variable you are dividing by and repeat the steps for multiplication 100/x < 20 (x) 100/x < 20 (x) 100x/x< 20 100<20x 20 20 X<5 Rule applies if it is greater than, greater than or equal too, or less than and equal too + Practice x/33 < 11 -5d/3 < 15 -y/6 > 48 500/v > 20 + When solving inequalities we graph the solution If the sign is less than or greater than: We draw a umber line Put a circle above the solved value Then draw a line from that circle to indicate the direction of all possible answers + When solving inequalities we graph the solution If the sign is less than or equal too or greater than or equal too: We draw a umber line Put a circle above the solved value Then draw a line from that circle to indicate the direction of all possible answers + Graph the following + Solve and Graph 5-X >10 -2X >12 + + 1. Get all numbers and variables on different sides 2. Get the variable alone 3x+5=12 -5 -5 3x=7 3 3 X= 7/3 + 1. Get all numbers and variables on different sides 2. Get the variable alone 4y-8=12 +8 +8 4y=20 4 4 X= 5 + 1. Get all numbers and variables on different sides 2. Get the variable alone 5m-4=-25 +4 +4 5m=-21 5 5 X= -21/5 + Practice + 1. Combine Like Terms 2. Get all numbers and variables on different sides 3. Get the variable alone 7x-3x-8=24 4x-8=24 +8 +8 4x=32 4 4 X= 8 + 1. Combine Like Terms 2. Get all numbers and variables on different sides 3. Get the variable alone 2/5x-1/5x+9=-1 1/5x+9=-1 -9 -9 (5/1)1/5x=-10 (5/1) X= -50 + 1. Combine Like Terms 2. Get all numbers and variables on different sides 3. Get the variable alone 25x-16x-24=-65 9x-24=-65 +24 +24 9x = -41 9 9 X= -41/9 + Practice + 1. Use the Distributive Property 2. Combine Like Terms 3. Get all numbers and variables on different sides 4. Get the variable alone 5x+3(x+4)=28 5x+3x+12=28 8x+12=28 -12 -12 8x = 16 8 8 X= 2 + 1. Use the Distributive Property 2. Combine Like Terms 3. Get all numbers and variables on different sides 4. Get the variable alone 4x+3(x-2)=21 4x+3x-6=21 7x-6=21 -6 -6 7x = 15 7 7 X= 15/7 + 1. Use the Distributive Property 2. Combine Like Terms 3. Get all numbers and variables on different sides 4. Get the variable alone 2x+5(x-9)=27 2x+5x-45=27 7x-45=27 -45 -45 7x = -28 7 7 X= -4 + Practice + Multi-Step Equations Just as with solving one-step or two-step or any equation, one goal in solving an equation is to have only variables on one side of the equal sign and numbers on the other side of the equal sign. The other goal is to have the number in front of the variable equal to one. The strategy for getting the variable by itself with a coefficient of 1 involves using opposite operations. The most important thing to remember in solving a linear equation is that whatever you do to one side of the equation, you MUST do to the other side. + Multi-Step Equations Solve + Multi-Step Equations We must first put the variables on the same side. Let’s move the 2x from the right side to the left side by subtracting 2x from both sides. + Multi-Step Equations Now we bring the constants over to the same side. Since we have a positive 9, we subtract 9 from both sides. + Multi-Step Equations Now to get the variable to have a coefficient of 1, we need to divide both sides of our coefficient by 2. + Multi-Step Equation + Multi-Step Equation 1. Move the Variables 2. Move the Constants 3. Get the Variable to have an exponent of 1 + Multi-Step Equations 1. Move the Variables 2. Move the Constants 3. Get the Variable to have an exponent of 1 + Multi-Step Equations 1. Distributive Property 2. Combine like terms 3. Move the Variables 4. Move the Constants 5. Get the Variable to have an exponent of 1 + Multi-Step Equations 1. Distributive Property 2. Combine like terms 3. Move the Variables 4. Move the Constants 5. Get the Variable to have an exponent of 1 + Multi-Step Equations + 2x 1. Get all numbers and variables on different sides 2. Get the variable alone -4 -4 2x 20 2 2 X = 10 + 1. Get all numbers and variables on different sides 2. Get the variable alone 5x 10 25 +10 +10 5x 35 5 5 X= 7 + b 1. Get all numbers and variables on different sides 2. Get the variable alone -b -1 b +2 +2 10 -1 10 + Practice + 1. Combine Like Terms 2. Get all numbers and variables on different sides 3. Get the variable alone n n+6 3 -3n + 6 -6 -6 -3 -3n -3 -3 n -6 + x 1. Combine Like Terms 2. Get all numbers and variables on different sides 3. Get the variable alone x 12x + 2 12x 12 x 1 -2 -2 2 12 + Practice + 1. Use the Distributive Property 2. Combine Like Terms 3. Get all numbers and variables on different sides 4. Get the variable alone (p ) - 3p + 3 -3p-3-3p+3 -6p -6 -6 p 3 + 1. Use the Distributive Property 2(x 2. Combine Like Terms 3. Get all numbers and variables on different sides 4. Get the variable alone ) + 2x + 3 37 2x+2+2x+3 37 4x+5 37 -5 -5 4x 32 4 4 X 8 + Practice + Absolute Value Solve the equation twice First time as if the absolute value symbols were parentheses Second time by changing all the sides inside the absolute value sign + Absolute Value + Absolute Value + Proportions Cross multiply and follow the steps for a multi-step equation + Proportions