Answer: 9x^3 + 27x^2
Step-by-step explanation:
The given functions are
f(x) = 3x + 9
g(x) = 3x^2
To find (fg)(x), we would multiply both functions. It becomes
(fg)(x) = 3x^2(3x + 9)
We would multiply each term inside the parentheses by the term outside. We have
3x^2 * 3x + 3x^2 * 9
= 9x^3 + 27x^2