Answer is (3,1)
x + y = 4
2x + 3y = 9
We multiply the first equation by -2 to eliminate x
-2x - 2y = -8
2x + 3y = 9
-------------------(add both equations)
0 + y = 1
So y =1
Now plug in 1 for y in first equation
x + y = 4
x + 1 = 4
Subtract 1 on both sides
x = 3
Answer is (3,1)