Answer
$g(x)=-\sqrt{x+2}$
Work Step by Step
The graph of $g$ is the result of shifting the graph of $f(x)=
\sqrt{x}
$ by $2$ units to the left and then reflecting about the $x-$axis. Hence, the equation of $g$ is
\begin{array}{l}\require{cancel}
g(x)=-\sqrt{x+2}
.\end{array}