Parameterize the curve by
[tex]\begin{cases}x(t)=t\\y(t)=4t^2\end{cases}[/tex]
with [tex]-3\le t\le1[/tex]. Then
[tex]\displaystyle\int_Cxy\,\mathrm dx+(x+y)\,\mathrm dy[/tex]
[tex]=\displaystyle\int_{-3}^14t^3\,\mathrm dt+(t+4t^2)(8t\,\mathrm dt)[/tex]
[tex]=\displaystyle\int_{-3}^1(8t^2+36t^3)\,\mathrm dt=\boxed{-\frac{1936}3}[/tex]