Answer:
x = 6 y = 15
Step-by-step explanation:
If this is simultaneous equations
x+y=21
3x-2y= -12
-3(x+y=21)
1(3x-2y= -12)
-3x -3y= -63
-5y= -75
y= -75/-5
y= 15
x+15=21
x=21-15
x=6
