nila x yang memenuhi sistem persamaan:2x+y-z=1,x+2y+3z=14,3x-y+2z=7

2x + y - z = 1
x + 2y + 3z = 14
3x - y + 2z = 7


persamaan 1 & 2

2x + y - z = 1 |×2|
x + 2y + 3z = 14 |×1|

4x + 2y - 2z = 2
x + 2y + 3z = 14
____________-
3x - 5z = -12 (1)


persamaan 2 & 3

x + 2y + 3z = 14 |×1|
3x - y + 2z = 7 |×2|

x + 2y + 3z = 14
6x - 2y + 4z = 14
_____________+
7x + 7z = 28 (bisa dibagi 7)
x + z = 4 (2)


… (1) & … (2)

3x - 5z = -12 |×1|
x + z = 4 |×5|

3x - 5z = -12
5x + 5z = 20
__________+
8x = 8
x = 1