-4x + 9y = 9...A
x - 3y = -6...B
Multiply B by 4. This will delete 4x.
-4x + 9y = 9
4x - 12y = -24
-3y = -15
y = -15/-3
y = 5
To find x, plug y = 5 into A or B.
I will use A.
-4x + 9y = 9
-4x + 9(5) = 9
-4x + 45 = 9
-4x = 9 - 45
-4x = -36
x = -36/-4
x = 9
Answer: x = 9, y = 5.