x-y+2z=9 dalam spltv eliminasi dan subtitusi, caranya bagaimana ya???

x - y + 2z = 9
2x + y - 3z = - 19
4x - 2y + z = 2

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

2x + y - 3z = - 19
2(9 + y - 2z) + y - 3z = - 19
18 + 2y - 4z + y - 3z = - 19
3y - 7z = - 19 - 18
3y - 7z = - 37

4x - 2y + z = 2
4(9 + y - 2z) - 2y + z = 2
36 + 4y - 8z - 2y + z = 2
2y - 7z = 2 - 36
2y - 7z = - 34

3y - 7z = - 37
2y - 7z = - 34
__________ —
y = - 3

2y - 7z = - 34
- 6 - 7z = - 34
- 7z = - 34 + 6
- 7z = - 28
z = 4

x = 9 + y - 2z
x = 9 - 3 - 8
x = 6 - 8
x = - 2

Maaf Kalau Salah