You can solve it by several ways, but easiest and shortest would be "By Elimination"
So, subtract 2nd equation from 1st,
-2x = 20
x = -10
Substitute it in 2nd equation,
-3(-10) + 9y = -6
30 + 9y = -6
9y = -6 - 30
y = -36/9
y = -4
In short, Your Answer would be: (-10, -4)
Hope this helps!