solve by elimination

Question

x + 3y - z = 2

x + y - z =0

3x + 2y - 3z = -1

Answer 1

x + 3y - z = 2

x + y - z =0

3x + 2y - 3z = -1

x=z+2-3y

x=z-y

z-y=z+2-3y

-y=2-3y

0=2-2y

-2=-2y

y=1

x+y-z=0

x+1-z=0

x+1=z

There is not enough information to answer this problem after that. Y is definitely 1, but x and z are any two numbers that are one away from each other. 9,1,10 works just as well as -5,1,-4