Question

Evaluate 3(x-4)+2x-x2 for x=5

A. -12
B. 0
C. -4
D. 40

Answer 1

A

Explanation:

Substitute x = 5 into the expression

3(5 - 4) + 2(5) - 5²

= (3 × 1 ) + 10 - 25 = 3 + 10 - 25 = 13 - 25 = - 12 → A

Answer 2

A. -12

Explanation:

First step.

Simplify the expression:

3(x - 4) + 2x - x² use the distributive property a(b - c) = ab - ac

= 3x - 12 + 2x - x² combine like terms

= -x² + (3x + 2x) - 12

= -x² + 5x - 12

Put x = 5 to the expression:

-5² + 5(5) - 12 = -25 + 25 - 12 = -12