Answer
$d=-16$
Work Step by Step
$$\begin{align*}
-2 \cdot \frac{d-8}{-2}&=-2 \cdot 12 &\text{Multiply -2 to both sides.}\\
d-8&=-24 &\text{Simplify.}\\
d-8+8&=-24+8 &\text{Add 8 to both sides.}\\
d&=-16 &\text{Simplify.}
\end{align*}$$
Check the answer by substituting $-16$ to the variable in the given equation.
$$\begin{align*}
\frac{d-8}{-2}&=12\\
\frac{-16-8}{-2}&\stackrel{?}{=}12\\
12&\stackrel{\checkmark}{=}12
\end{align*}$$
Thus, the solution is $d=-16$.
