Answer
$q=r-2p$
Work Step by Step
$\bf{\text{Solution Outline:}}$
To solve the given equation, $
p=\dfrac{r-q}{2}
$ for $
q
,$ use the properties of equality to isolate the variable.
$\bf{\text{Solution Details:}}$
Using the properties of equality to isolate the variable, the equation above is equivalent to
\begin{array}{l}\require{cancel}
p=\dfrac{r-q}{2}
\\\\
2\cdot p=2\cdot \dfrac{r-q}{2}
\\\\
2p=r-q
\\\\
q=r-2p
.\end{array}