2x-y+z=6 x-3y+z=-2 x+2y-z=3

x-3y+z = -2
x = 3y-z-2

2x-y+z=6
2(3y-z-2)-y+z=6
6y-2z-4-y+z=6
5y-z=10 ...... (1)

x+2y-z= 3
(3y-z-2)+2y-z=3
5y-2z=5 ...... (2)

Eliminasi :
5y-z=10
5y-2z=5
_______ -
z = 5
y = 5y-5=10
y = 3
x : x+2y-z=3
>> x+6-5=3
>> x+1 = 3
x = 2