-x+y=-3, 3x+2y=9
1. multiply the first row by the second
-2x+2y=-6, 3x+2y=9
2. subtract the second row from the first row
-5x=-15
3. sole for x in the above equation
x=-15/-5
x=15/5
x=3
4. substitue x=3 into -2x+2y=-6
-2*3+2y=-6
5. solve for y in the above equation
-6+2y=-6
2y-6=-6
2y=0
y=0
6 therefore,
x=3 and y=0
Have a nice day :D