Answer
$h(x) = f(g(x)) = (2x + 3)^{7}$
$f(x) = x^{7}$
$g(x) = 2x + 3$
Work Step by Step
Since the expression $2x + 3$ is elevated to the seventh power, it's tempting to simply use that same expression as a variable in a function:
$$(2x + 3)^{7}$$
$$X^{7}$$ where $X = (2x + 3)$. As such, we can say that $f(X) = X^{7}$ and $g(x) = 2x + 3$. Now, we can say that $f(g(x)) = (2x + 3)^{7}$.
