x,y,z adalah penyelesaian sistem persamaan : x-y=1 x+z=-1 3x+8z=3

x + z = -1
x = -1 - z

subs ke pers.3
3(-1-z) + 8z = 8
-3 -3z + 8x = 8
5z = 11
z = 11/5

subs ke pers. 2
x + 11/5 = -1
x = -5/5 -11/5
x = -16/5

subs ke. pers 1
-16/5-y = 1
-y = 5/5 +16/5
y = -21/5