Answer
\[\int_{1}^{2}{\int_{x+1}^{2x+4}f(x,y) {dy}dx}\]
Work Step by Step
\[\begin{align}
& \text{Let the region} \\
& R=\left\{ \left( x,y \right):1\le x\le 2,\text{ }x+1\le y\le 2x+4 \right\} \\
& \text{Then,} \\
& \int_{1}^{2}{\int_{x+1}^{2x+4}f(x,y) {dy}dx} \\
& \text{Graph} \\
\end{align}\]
