###### Example3.3.3

Solve for \(R\) in \(P=R-C\text{.}\) (This is the relationship between profit, revenue, and cost.)

To solve for \(R\text{,}\) we first want to note that \(C\) is *subtracted* from \(R\text{.}\) To “undo” this, we will need to *add* \(C\) to each side of the equation:

\begin{align*}
P\amp=\attention{R}-C\\
P\addright{C}\amp=\attention{R}-C\addright{C}\\
P+C\amp=\attention{R}\\
R\amp=P+C
\end{align*}