;)
Hola Johana!
$$\begin{align}&\oint_Rf(s) \,ds=\iint_R\Big( \frac{\partial Q}{\partial x}-\frac{\partial P }{\partial y} \Big)dxdy\\&\\&Donde \ el \ campo\ vectorial \ es:\\&\\&\oint_Rf(s) \,ds=\oint_RP(x,y)dx+Q(x,y)dy\\&\\&En \ tu \ caso\\&\\&P(x,y)=Q(x,y)=e^{x+y}\\&\\&\oint_RP(x,y)dx+Q(x,y)dy=Teorema \ Green=\\&\\&\iint_R\Big( \frac{\partial Q}{\partial x}-\frac{\partial P }{\partial y} \Big)dxdy=\\&\\&\frac{\partial Q}{\partial x}=\frac{\partial P }{\partial y}=e^{x+y}\\&\\&\iint_R \Big( e^{x+y}-e^{x+y} \Big) dxdy=\iint_Rdxdy\\&\\&\\&\\&\\&\end{align}$$
esa integral doble es el área del recinto, que es una circunferencia de radio 2, luego:
$$\begin{align}&\iint_Rdxdy= \pi r^2= 4 \pi\\&\\&O \ haciendo \ la \ integral \ doble \ en \ polares:\\&\\&\iint_Rdxdy= \int_0^2 \Bigg[ \int_0^{2 \pi} r\ \ d \theta\ \Big]dr= \int_0^2 \Bigg[ r \theta \Bigg]_0^{2 \pi} \ \ dr=\\&\\&\int _0^22 \pi r \ dr= \pi r^2 \Bigg|_0^2=\ 4 \pi\end{align}$$