Answer
\[\int_{0}^{1}{\int_{x}^{-x+2}{f\left( x,y \right)}}dydx\]
Work Step by Step
\[\begin{align}
& \text{The region }R\text{ is represented in the graph shown below} \\
& R=\left\{ \left( x,y \right):x\le y\le -x+2,\text{ }0\le x\le 1 \right\} \\
& \text{Then,} \\
& \iint_{R}{f\left( x,y \right)}dA=\int_{0}^{1}{\int_{x}^{-x+2}{f\left( x,y \right)}}dydx \\
\end{align}\]
