Simplify (x2 + 16) (x2 - 16) = ?

A. x4 - 32

B. x4 + 32

C. x4 + 256

D. x4 - 256

You multiply by distributing each term.

(x^2 + 16) (x^2 - 16)

= x^4 - 16x^2 + 16x^2 - 256

= x^4 - 256

So the answer is D

(x² + 16) (x + 8) (x - 2)

(x² + 16) (x (x - 8) + 8 (x - 2))

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

(x² + 16) (x² - 8x + 8x - 16)

(x² + 16) (x² - 16)

x² (x² - 16) + 16 (x² - 16)

x² (x²) - x² (16) + 16 (x²) - 16 (16)

x⁴ - 16x² + 16x² - 256

x⁴ - 256

The answer is D.