To find the solutions, we multiply the first equation by 2, then we sum the equations to solve for y.
[tex]\begin{gathered} \begin{cases}4x+14y=-62 \\ -4x-4y=-8\end{cases}\rightarrow10y=-70 \\ y=-\frac{70}{10} \\ y=-7 \end{gathered}[/tex]Then, we use y = -7 to find x
[tex]\begin{gathered} 2x+7y=-31 \\ 2x+7(-7)=-31 \\ 2x-49=-31 \\ 2x=-31+49 \\ 2x=18 \\ x=\frac{18}{2} \\ x=9 \end{gathered}[/tex]