diketahui x+2y = -3 , 3x-2y-3z = 7 , 4x-y+z =6 . maka z =??

x=-3-2y

substitusi x
3(-3-2y)-2y-3z=7
-9-6y-2y-3z=7
-8y-3z=16 (i)

4(-3-2y)-y+z=6
-9y+z=18 (ii)


eliminasi (i) dan (ii)
z=0