Question

2(x+y)-x=-6
3x-(x-y)=0

Answer 1

2(x+y)-x=-6
2x+2y-x=-6
x+2y=-6
x=-6-2y
y=(x-6):2
y=(x:2)-3

3x-(x-y)=0
3x-x+y=0
2x+y=0
y=0-2x
x=(0-y):2
x=0-y