Opener (5 + 6) • 2 a + (b + c) + (d • e) 18k - 24 2x2 + 5x + 4y + 7 Use each named property to write an equivalent expression. Commutative property of multiplication: 2 • (5 + 6) Associative property of addition: (a + b) + c + (d • e) Distributive property: 6(3k - 4) Combine like terms: 2x2 + 10 + 7x + 3y – 2x + y – 3; then name the coefficient(s) and the constant(s). (5 + 6) • 2 a + (b + c) + (d • e) To be used for general review 18k - 24 2x2 + 5x + 4y + 7 2, 5, 4; 7

Objective □ I will be able to use subtraction and addition to solve equations.

Vocabulary inverse operation – an operation that “undoes” another operation. equation – two expressions, with the same values, set equal to one another

We need to isolate the variable (get the “x” by itself) Solving an Equation We need to find the missing value that will make this equation true: 5 + x = 10 We need to isolate the variable (get the “x” by itself)

The Golden Rule of Algebra “What you do to one side of the equation, you must do to the other.”

Ex 1 – Using Subtraction to Solve Solve 214 = y + 112. 214 = y + 112 - 112 - 112 Subtract 112 from both sides 102 = y + Simplify 102 = y Check your answer: 214 = y + 112 214 = 102 + 112 214 = 214

Ex 2 – Using Subtraction to Solve Solve z + 4.7 = 10.3. z + 4.7 = 10.3 - 4.7 - 4.7 Subtract 4.7 from both sides z + = 5.6 Simplify z = 5.6 Check your answer: z + 4.7 = 10.3 5.6 + 4.7 = 10.3 10.3 = 10.3

Ex 3 – Using Addition to Solve Solve x - 31 = 14. x - 31 = 14 + 31 + 31 Add 31 to both sides x - = 45 Simplify x = 45 Check your answer: x - 31 = 14 45 - 31 = 14 14 = 14

Ex 4 – Using Addition to Solve Solve 0.5 = y – 1.25. 0.5 = y – 1.25 + 1.25 + 1.25 Add 1.25 to both sides 1.75 = y - Simplify 1.75 = y Check your answer: 0.5 = y - 1.25 0.5 = 1.75 – 1.25 0.5 = 0.5

Homework WB 2.5 (#1-19 & #24-26)