Question

select the correct answer.
which number is a zero of $h(x)=(x^2 - 81)(x + 4)$
a. 0
b. 4
c. 9
d. 81

Explanation:

Step1: Set function to 0

$$(x^2 - 81)(x + 4) = 0$$

Step2: Factor difference of squares

$$(x - 9)(x + 9)(x + 4) = 0$$

Step3: Solve for x

Set each factor to 0:
$x - 9 = 0 \implies x = 9$
$x + 9 = 0 \implies x = -9$
$x + 4 = 0 \implies x = -4$

Answer:

C. 9