x+y+z =-3 x-y =7 2x + 2y -z =6

x+y+z =-3 persamaan 1
x-y =7 persamaan 2
2x + 2y -z =6 persamaa 3


.Eliminasi pers. 1 dan pers. 2
x+y+z = -3
x-y =7
------------ --
2y + z = - 10 persamaan 4


.Eliminasi pers. 2 dan pers. 3
x-y =7 (×2)
2x + 2y -z =6
..
2x - 2y = 14
2x + 2y - z = 6
------------------- --
- 4y + z = 8 persamaan 5


. Eliminasi pers. 4 dan pers. 5
2y + z = - 10
- 4y + z = 8
---------------- -
6y = - 18
y = - 18/6
y = - 3

2y + z = - 10
2(-3) + z = - 10
- 6 + z = - 10
z = - 10 + 6
z = - 4

x+y+z =-3
x + (-3) + (-4) = - 3
x - 3 - 4 = - 3
x - 7 = - 3
x = - 3 + 7
x = 4

jadi x = 4, y = - 3, z = - 4