[tex]\begin{cases}-2x^2+y=-5\\y=-3x^2+5\end{cases}\\\\\\
-2x^2+(-3x^2+5)=-5\\\\
-2x^2-3x^2+5=-5\quad|-5\\\\-5x^2=-10\quad|:(-5)\\\\x^2=2\\\\
\boxed{x=-\sqrt{2}\qquad\vee\qquad x=\sqrt{2}}\\\\\\
y=-3x^2+5\qquad\vee\qquad y=-3x^2+5\\\\
y=-3(-\sqrt{2})^2+5\qquad\vee\qquad y=-3(\sqrt{2})^2+5\\\\
y=-3\cdot2+5\qquad\vee\qquad y=-3\cdot 2+5\\\\
y=-6+5\qquad\vee\qquad y=-6+5\\\\
\boxed{y=-1\qquad\vee\qquad y=-1}\\\\\\
\begin{cases}x=-\sqrt{2}\\y=-1\end{cases}\qquad\vee\qquad\begin{cases}x=\sqrt{2}\\y=-1\end{cases}[/tex]
Answer C.
