Question

Which expression is equivalent to 8x3 − 64 when factored completely?

a
(2x − 4)(4x2 + 8x + 16)

b
(2x − 4)(4x2 − 8x + 16)

c
(2x + 4)(4x2 + 8x + 16)

d
(2x + 4)(4x2 + 8x − 16)

Answer 1

A (2x − 4)(4x2 + 8x + 16)

Explanation:

A

(2x − 4)(4x2 + 8x + 16) =

8x3 + 16x2 + 32x - 16x2 - 32x - 64 =

8x3 - 64

B

(2x − 4)(4x2 − 8x + 16)

8x3 - 16x2 + 32x - 16x2 + 32x - 64

8x3 - 32x2 - 64

c

(2x + 4)(4x2 + 8x + 16)

8x3 + 16x2 + 32x + 16x2 + 32x + 64

8x3 + 32x2 + 64x + 64

D

(2x + 4)(4x2 + 8x − 16)

8x3 + 16x2 - 32x + 16x2 + 32x - 64

8x3 + 32x - 64