Answer
$1$
Work Step by Step
RECALL:
$g(a)$ represents the value of the function $g$ when $x=a$.
To find the value of $x$ such that $g(x)=-1$, imagine the line $y=-1$ and check the points on the graph where the line will pass through.
Notice that the horizontal line $y=-1$ will pass through the graph at exactly one point: $(1, -1)$.
Thus, $g(1) = -1$.
Therefore the value of $x$ for which $g(x) = -1$ is $1$.