Answer:
(x, y) = (8, -3)
Explanation:
You can substitute for x in the first equation:
3(-3y -1) +3y = 15
-6y = 18 . . . . . add 3 and simplify
y = -3 . . . . . . . divide by -6
x = -3(-3) -1 = 8 . . . . find x using the second equation
The solution to this system of equations is (x, y) = (8, -3).