2x +y=9 X - z =1 z - y= - 4 Tentukan nilai X, Y, Z

2x + y = 9
y = - 2x + 9

z - y = - 4
z - ( - 2x + 9 ) = - 4
z + 2x - 9 = - 4
z + 2x = - 4 + 9
z + 2x = 5

x - z = 1
- z + x = 1

z + 2x = 5
- z + x = 1
---------------(+)
3x = 6
x = 2

z + 2x = 5
z + 2(2) = 5
z + 4 = 5
z = 5 - 4
z = 1

z - y = - 4
1 - y = - 4
- y = - 4 - 1
- y = - 5
y = 5

hp = ( 2 , 5 , 1 )