Answer
$-6$
Work Step by Step
Find the corresponding value of $f(0)$ on the graph since we are plugging the corresponding value of $f(0)$ into $g(x)$ and finding the corresponding value of $g(f(x))$ on the graph as well.
$f(0)=2$
$g(2)=-6$
$g(f(x))=g(f(0))=g(2)=-6$
