X-3y=9

2x-y=-2

X-3y=9

2x-y=-2

x = 9 + 3y

Now, substitute the value for x in the other equation.

2(9 + 3y) - y = -2
18 + 6y - y = -2
5y = -20
y = -4

x - 3(-4) = 9
x + 12 = 9
x = -3