The solution to the system of equations is x = -15 and y = -27.
We'll eliminate one variable by multiplying the second equation by 2 and adding it to the first equation to create an upper triangular system.
Multiplying the second equation by 2 gives:
-4x + 2y = 6
Now, adding this modified second equation to the first equation:
-4x - 3y = 21
(-4x + 2y = 6)
From this, we find that y = -27.
Now, substitute y = -27 into the second equation to find x:
-2x + y = 3
-2x - 27 = 3
-2x = 3 + 27
-2x = 30
x = 30 / (-2)
x = -15