Answer
$g(f(x)) = x^{2} - 2$
Work Step by Step
$$f(x) = x^{2} - 4 / g(x) = x + 2$$
The exercise asks us to find $g(f(x))$; which means we simply have to substitute $f(x)$ for every term $x$ in the function $g(x)$:
$g(f(x)) = (x^{2} - 4) + 2$
$g(f(x)) = x^{2} - 4 + 2$
$g(f(x)) = x^{2} - 2$
