1/3x+1/2y-z=7 1/6x+1/4y-1/3z=1 1/2x+2/3y-1/2z=-6

2x + 3y - 6z = 42

2x + 3y - 4z = 12

3x + 4y - 3z = -36

Selesaikan persamaan
2x + 3y - 6z = 42
2x + 3y - 4z = 12  -

-2z = 30
z = -15

Masukkan harga z di pers (1) dan (3)
2x+3y - 6(-15) = 42
2x+3y+90 = 42
2x+3y = - 48

3x+4y - 3(-15) = -36
3x+4y +45 = -36
3x+4y = -81

Selesaikan 2 persamaan baru ini
2x+3y = - 48
3x+4y = - 81

6x+9y = -144
6x+8y = -162 -
y = 18
maka
x = [-48 - 3(18)]/2
x = -51

Jadi
x = -51
y = 18
z = -15