1. 9y = -3x - 39....add 3x to both sides
3x + 9y = -39 <== standard form
2. -2x + 2y = -2. ..multiply by -1
2x - 2y = 2 <== standard form
3. -2x = 20
x = -20/2
x = -10....now sub this back into the second equation
3x - 4y = -2
3(-10) - 4y = -2
-30 - 4y = -2
-4y = -2 + 30
-4y = 28
y = -28/4
y = -7
solution is (-10,-7) <== solution