5y-8z=-19 5x-8z=6 3x-2y=12

5y - 8z = -19
5x - 8z = 6
------------------ -
5y - 5x = -25 | kali 2
3x - 2y = 12  | kali 5

10y - 10x = -50
-10y + 15x = 60
--------------------+
 5x = 10
x = 2

substitusikan untuk mencari y
3x - 2y = 12
3(2) - 2y = 12
6-2y=12
-2y=6
y = -3

5y - 8z = -19
5(-3) - 8z = -19
-8z=-4
z = 1/2