2x - 2y = -12
4x - 7y = -15
Multiply the first equation by -2 to make the 2x the opposite of 4x:
2x - 2y = -12 x -2 = -4x + 4y = 24
Now add this to the second equation:
-4x + 4y = 24 + 4x - 7y = -15:
-3y = 9
Divide both sides by -3
y = 9 / -3
y = -3
Now you have Y, replace y in one of the equations and solve for x:
2x - 2(-3) = -12
2x +6 = -12
Subtract 6 from both sides:
2x = -18
Divide both sides by 2:
x = -18 /2
X = -9
Check:
2(-9) - 2(-3) = -12
-18 + 6 = -12 TRUE
4(-9) - 7(-3) = -15
-36 +21 = -15 TRUE
X = -9, y = -3
(-9,-3)
