Selesaikan kelompok tiga persamaan dengan variabel tidak diketahui berikut : 2x + 3y - z = - 5 x-4y+2z = 21 5x + 2y - 3z = - 4

2x + 3y - z = -5
x - 4y + 2z = 21 (dikalikan 2)
2x + 3y -z = -5
2x - 8y + 4z = 42
lalu x dieliminasi
11y - 5z = -47

x - 4y + 2z = 21 (dikalikan 5)
5x + 2y - 3z = -4
5x - 20y + 2z = 105
5x + 2y - 3z = -4
lalu x dieliminasi
-22 y + 5z = 109

-22y + 5z = 109
11 y - 5z = -47 (dikalikan 2)
-22y + 5z = 109
22 y - 10z = -94
lalu y dieliminasi dngn cara dijumlahkan
-5z = 15
z = -3

11y - 5z = -47
11y - 5(-3) = -47
11y + 15 = -47
11y = -62
y = -62/11
y = -5 7/11

5x + 2y -3z = -4
5x -124/22 + 9 = -4
5x -124/22 = -13
5x = -13 + 124/22
5x = -286/22 + 124/22
5x = -162/22
x = -81/11 : 5
x = -81/55
x = -1 26/55