tolong jawab ya pake caranya

2x + y = 9
2x + z = 5
-------------- -
y - z = 4
y + z = 2
----------- +
2y = 6
y = 6/2 = 3
dari y + z = 2
3 + z = 2
z = 2-3 = -1
dari 2x + y = 9
2x + 3 = 9
2x = 9-3
2x = 6
x = 6/2 = 3
HP = { (3, 3, -1) }