Answer:
x = -6
y = 3
Step-by-step explanation:
Since we are given what x equals, we will plug that in first to the second equation.
(-3y+3) - 3y = -15
Solve by combining like-terms and isolating y.
-6y + 3 = -15
-6y = -18
y = 3
Now plug in y to the first equation to solve for x.
x = -3(3) + 3
x = -9 + 3
x = -6