Answer:
[tex]y=-7[/tex] is the answer.
Step-by-step explanation:
[tex]\begin{bmatrix}x+y=-4\\ x-y=10\end{bmatrix}[/tex]
Multiply the second equation with -1 and add them.
[tex]\begin{bmatrix}x+y=-4\\ -x+y=-10\end{bmatrix}\\\\\\\rightarrow 2y=-14\\\\\rightarrow y=-7[/tex]
