X+2y=-4 2x+z=5 y-3z=-6

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

kemudian -4y + z = 13 ==> z = 13 + 4y substitusi ke y - 3z = -6 ==> y - 3(13 + 4y) = -6 ==> y - 39 - 12y = -6 ==> -11y = 33 ==> y = -3

x = -4 + 6
x = 2
z = 5 - 4
z= 1

{ x, y, z } = { 2,-3, 1 }