Question

Which of the following represents the factorization of the binomial below?

X^2-81


A (x-9)(x-9)

B (x)(x-81)

C (x+9)(x+9)

D (x+9)(x-9)

Answer 1

D

Explanation:

x² - 81 ← is a difference of squares and factors in general as

a² - b² = (a + b)(a - b)

Here a = x and b = 9, thus

x² - 81 = (x + 9)(x - 9) → D