Tentukan nilai x , y , z 2x + 3y - z = 5 ........ (1) x + y + z = 9........... (2) x - 2y - z = -7 .......... (3)

2x+3y-z=5
x-2y-z=-7

(1) 2x+3y-z=5
2x-4y-2z=-14
-7y+z=19 .…(1)

x-2y-z=-7
x+y+z=9

-3y-2z=-16
3y+2z=16… (2)


(1)(2)
3y+2z=16
-7y+z=19

3y+2z=16
-14y+2z=38

17y=22
y=22/17