-7x -y = -12
4x +y = 6
add the equations
-7x -y = -12
4x +y = 6
-3x +0y = -6
simplify
-3x = -6
solve for x
x = 2
pick one of the original equations
4x +y = 6
enter the value for x
4(2) +y = 6
solve for y
8 +y = 6
y = -2
Answer: x = 2, y = -2
check:
-7x -y = -12
-7(2) -(-2) = -12
-14 +2 = -12 True
check:
4x +y = 6
4(2) +(-2) = 6
8 - 2 = 6 True