Question

1. Which expression is equivalent to the expression shown

below? 20 + 8y – 9y – 21
A. 2(10 + 4y – 7y - 19)
B. 2(10 + 4y) – 3(3y - 7)
C. 4(5 + 2y – 5y - 17)
D. 4(5 + 2y) – 3(3y + 7)
E. -(y + 1)
F. -(1- y)
G. y - 1

Answer 1

• D and E

Explanation:

There are two kinds of expressions in the choices:

• factored and simplified

Let's find the equivalent expression:

• 20 + 8y - 9y - 21

Factored one:

• 20 + 8y - 9y - 21 =
• 4(5 + 2y) - 3(3y + 7)

The matching choice is D

Simplified:

• 20 + 8y - 9y - 21 =
• 20 - 21 + 8y - 9y =
• - y - 1 =
• - (y + 1)

The matching choice is E