We have to solve the linear system:
-6x - y = 9
-2x + 10y = -28
Multiply both sides of the first equation by 10:
-60x - 10y = 90
-2x + 10y = -28
Now sum both equations, we get:
-60x - 2x -10y + 10y = 90 - 28
-62x + 0 = 62
-62x = 62
x = 62 / -62
x = -1
Now lets find y. I'm going to use the first equation since it is easier to do the math:
-6x - y = 9
-6(-1) - y = 9
6 - y = 9
-y = 9 - 6
-y = 3
y = -3
So the solution of the linear system is x = -1, y = -3 or simply (-1, -3).
Answer: x = -1 ; y = -3
