Elimination -12x -8y=-20 -3x +9y=-27
Divide both sides of Eq1 by (-4):
Eq1: +3x + 2y = 5
Eq2: -3x + 9y = -27
Sum: 11y = -22
Y = -2
In Eq1, replace Y with (-2) and solve for X:
3x + 2*(-2) = 5
3x - 4 = 5
3x = 9
X = 3
Solution set: (x,y) = (3,-2)