Answer
$q=1$
Work Step by Step
$$\begin{align*}
11-12&=12-q-12 &\text{Subtract 12 from each side.}\\
-1&=-q &\text{Simplify.}\\
-1(-1)&=-q(-1) &\text{Mulitply -1 to both sides.}\\
1&=q &\text{Simplify.}\\
\end{align*}$$
Check the answer by substituting $1$ to the variable in the given equation.
$$\begin{align*}
11&=12-q\\
11&\stackrel{?}{=}12-1\\
11&\stackrel{\checkmark}{=}11
\end{align*}$$
Thus, the solution is $q=1$.
