Question

8
select the correct answer.
consider these functions:
$f(x) = 3x^3 + 8x - 2$
$k(x) = 4x$
what is the value of $k(f(x))$?
a. $192x^3 + 8x - 2$
b. $192x^3 + 32x - 2$
c. $12x^3 + 32x - 2$
d. $12x^3 + 32x - 8$

Explanation:

Step1: Substitute $f(x)$ into $k(x)$

$k(f(x)) = 4 \times f(x)$

Step2: Plug in $f(x)$ expression

$k(f(x)) = 4(3x^3 + 8x - 2)$

Step3: Distribute the 4 to each term

$k(f(x)) = 4\times3x^3 + 4\times8x - 4\times2 = 12x^3 + 32x - 8$

Answer:

D. $12x^3 + 32x - 8$