HP penyelesaian persamaan {x+y+z=2 2x-y+z=-1 x-y-z=0

x+y+z =2
2x-y+z =-1
__________-
-x +2y = 3

2x-y+z=-1
x-y-z = 0
_________+
3x - 2y = - 1

-x+2y = 3
3x-2y = - 1
___________+
2x = 2
x = 1

3x - 2y = - 1
3(1)-2y = - 1
-2y = - 1 - 3
-2y = - 4
y = 2

x-y-z = 0
1-2-z =0
-1-z = 0
-z = 1
z= - 1

(x, y dan z = 1,2 dan - 1)