4x-y = 15
3x+2y = -8
Multiplying the first equation by two makes for an easy elimination of the y variable.
8x - 2y = 30
3x + 2y = -8
Add vertically.
11x = 22.
Divide by 11 on both sides and get x = 2.
Plug into an equation.
4(2) - y = 15
8 - y = 15
8 = 15 + y
8 - 15 = y
-7 = y.
Thus the solution is indeed (2, -7).