Tentukan himpunan penyelesaiannya!

1 - 2
5y - 5x = -25 ... 4

4' - 3'
-10x + 10y = -50
15x -10y = 60

5x = 10
x = 2

sub. x = 2 ke 3
6 - 2y = 12
-2y = 6
y = -3

sub. x = 2 ke 2
10 - 8z = 6
- 8z = -4
z = 1/2

HP : { 2, -3, 1/2 }