X+2y+4z=3 2z=-8+2x 3x=3y+3

x+2y+4z=3.. pers 1
z=-4+x ... pers 2
x=y+1 .. pers 3
subs pers 3 ke pers 2
z= -4+y+1
z= y-3 ... pers 4
subs pers 4 ke pers 1
x+2y+4y-12=3
x+6y=15 .. pers 5
subs pers 3 ke pers 5z
y+1+6y=15
7y=14
y= 2
.. cari x
x=y+1
x= 2+1
x=3
cari z
z= y-3
z=2-3
z= -1
jadi x= 3 , y = 2 dan z = -1