Question

x+y+z=3

x+y-z=1

x-y-z=-1

Answer 1

x+y+z-(x+y-z)=3-1

x+y+z-x-y+z=2

2z=2

z=2

 

x+y-z-(x-y-z)=1-1

x+y-z-x+y+z=0

2y=0

y=0

 

x+0+2=3

x=1