Page 69 - Math Course 2 (Book 1)
P. 69
Commutative and Associative Properties
Simplify the expression and indicate the properties used.
3(3x + 2y) + 5(x + 4y) = 3(3x) + 3(2y) + 5(x) + 5(4y) Distributive Property
= 9x + 6y + 5x + 20y Multiply.
= 9x + 5x + 6y + 20y Commutative (+)
= (9x + 5x) + (6y + 20y) Associative (+)
= (9 + 5)x + (6 + 20)y Distributive Property
= 14x + 26y Add
Your Turn!
Write and Simplify an Expression
Use the expression f ve times the sum of 2x and 3y Simplify the expression.
increased by 2 times the sum of x and 6y. Write an
algebraic expression for the verbal expression. A. 14x + 21y
A. (2x + 3y) + (x + 6y) B. 12x + 9y
B. 7(2x + 3y) C. 21x + 9y
C. 5(2x + 3y) + 2(x + 6y) D. 12x + 27y
D. (10x + 3y) + (2x + 6y)
Answer Answer
Skill Practice!
Evaluate each expression.
1. 16 + 8 + 14 + 12 2. 36 + 23 + 14 + 7 3. 32 14 18 11
4. 5 • 3 • 4 • 3 5. 2 • 4 • 5 • 3 6. 5 • 7 • 10 • 4
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