x+2y=-4 2x+z=5 y-3z=-6 tentukan nilai x, y, z?

x + 2y = -4
x = -2y - 4

substitusi
2x + z = 5
2(-2y - 4) + z = 5
-4y - 8 + z = 5
-4y + z = 5 + 8
-4y + z = 13

Eliminasi
-4y + z = 13 (x1)
y - 3z = -6 (x4)
------------------------
-4y + z = 13
4y - 12z = -24
------------------------- +
-11z = -11
z = 1

-4y + z = 13
-4y + 1 = 13
-4y = 13 - 1
-4y = 12
y = -3

x = -2y - 4
x = -2(-3) - 4
x = 6 - 4
x = 2

maka
x = 2
y = -3
z = 1