Answer
$x=8$.
Work Step by Step
The given function is
$\Rightarrow g(x)=-\frac{1}{2}x+3$
Substitute $-1$ for $g(x)$.
$\Rightarrow -1=-\frac{1}{2}x+3$
Subtract $3$ from each side.
$\Rightarrow -1-3=-\frac{1}{2}x+3-3$
Simplify.
$\Rightarrow -4=-\frac{1}{2}x$
Multiply each side by $-2$.
$\Rightarrow -2(-4)=-2(-\frac{1}{2}x)$
Simplify.
$\Rightarrow 8=x$.
