Algebra II September 8, 2005

Drill (solve for each variable) 1) 2) 3)

Objective Today we will learn to use the rules of combining like terms and the distributive property to solve equations.

Combine Like Terms In order to combine like terms the terms must have the exact same variable expression or simply have no variable expression in them.

Examples 2x and 3x are like terms because they have the same variable expression. 2a and are not like terms because they do not have the same variable expression.

Rules Once you find your like terms you either add or subtract the coefficients (the numbers in front of the variables) and the variable expressions stay the same.

Examples 1) 2x + 3x + 6a – 2a + 2x 2) 3s + 3) 4a – 2b + 4a – 3b + 3c

Distributive Property Anytime you have a number or expression next to parentheses it means to multiply the number or expression by each term inside of the parentheses.

Step one 5 multiplied by 2x is equal to 10x Examples 5(2x + 3) Step one 5 multiplied by 2x is equal to 10x Step two 5 multiplied by a +3 is +15 Therefore 5(2x + 3) is 10x +15

Step one -3 multiplied by 8x is equal to -24x Examples -3(8x – 4) Step one -3 multiplied by 8x is equal to -24x Step two -3 multiplied by a -4 is +12 Therefore -3(8x – 4) is -24x +12

4(3x + 2) = 32 4(3x) + 4(2) = 32 12x + 8 = 32 - 8 -8 12x = 24 x = 2 Examples 4(3x + 2) = 32 4(3x) + 4(2) = 32 12x + 8 = 32 - 8 -8 12x = 24 x = 2

Algebra Word Problems Ex: 3 times the sum of 2 times a number and 4 is equal to 36. Write an equation to represent the word problem SOLVE

Classwork Page 25 #’s 43, 44, 47 – 54 Page 27 #’s 79 - 82