3x-4y=1-m
2x+3y=3+2m
5x-y=4+m
5x-2y=2
y=2+m
5x=6+2m
x=(6+2m)/5
(18+6m)/5-8-4m=1-m
18+6m-40-20m=5-5m
9m=-27
m=-3