Answer:
x = 13/8
y = -45/8
Explanation:
9x + y = 9
3x + 3y = -12
Divide the second equation by 3
x+y = -4
Multiply this by -1
-x -y = 4
Add this to the first equation to eliminate y
9x + y = 9
-x -y = 4
-----------------
8x +0 = 13
Divide by 8
8x/8 = 13/8
x = 13/8
Now find y
x+y = -4
13/8 +y = -4
Subtract 13/8 from each side
13/8 -13/8 +y = -4-13/8
y = -32/8 - 13/8
y = -45/8