x+2y-4z=-7 2x+4y-4z=-6 x+y+2z=4

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

Eliminasi x dari (1 dan (2
x + 2y - 4z = -7 |.2| 2x + 4y - 8z = - 14
2x + 4y - 4z = -6|.1| 2x + 4y - 4z = - 6 _
- 4z = -8
Z = 2
Eliminasi x dari (1 dan (3
x + 2y - 4z = -7
x + y + 2z = 4 _
y - 2z = - 11........ (3
Substitusi z = 2 ke pers. (3
y - 2(2) = - 11
y - 4 = - 11
y = -7
Substitusi z = 2, y = - 7 ke pers. (3
x -7 + 2(2) = 4
x -7 + 4 = 4
x = 7
Jadi, hp nya (7, -7, 2)