nilai fariabel x,y,& z dari ke 3 persamaan berikut 1.x=x+2y-z 2.2x+2y+2z=14 3.y+3z=7

1. x - x = 2y - z
0 = 2y - z
z = 2y (pers. 1)
2. 2 (x + y + z) = 14
x + y + z = 7 (pers.2)
3. y + 3z = 7
y + 3(2y) = 7
y + 6y = 7
7y = 7
y = 1

y + 3z
1 + 3z = 7
3z = 6
z = 2

x + y + z = 7
x + 1 + 2 = 7
x = 4