The graph below shows a system of equations:The x-coordinate of the solution to the system of equations is __________.

3y = -2x + 2
y = x + 4 (Substitute the y)

3(x + 4) = -2x + 2 (Distribute)
3x + 12 = -2x + 2 (Add 3 to both sides)
+3x       +3x
------------------------------------------
12 = 1x + 2 (Subtract 2 from both sides)
-2         - 2
------------------------
10 = 1x (Divide by 1 on both sides)
10/1 = 1x/1
x = 10 
This is your x-coordinate