1. tentukan himpunan penyelesaian dari SPLTV berikut dengan cara eliminasi x-2y+z=2 2x+y+2z=1 -x+y+=2 2. tentukan himpunan penyelesaian dari SPLTV berikut denga

1) x - 2y + z = 2 |×2
2x + y + 2z = 1 |×1
2x - 4y + 2z = 2
2x + y + 2z = 1
------------------------ (-)
- 5y = 1
y = - 1/5 ... pers 1
2x + y + 2z = 1 |×1
-x + y + z = 2 |×2
2x + y + 2z = 1
-2x + 2y + 2z = 4
-------------------------(-)
4x + 3y = - 3 ... pers 2
pers 1 & 2
4x + 3y = - 3
4x + 3(-1/5) = - 3
4x - 3/5 = - 3
4x = - 3 + 3/5
4x = - 2 2/5
4x = - 12/5
x = - 12/5 ÷ 4
x = - 12/5 × 1/4
x = - 3/5
x - 2y + z = 2
- 3/5 - 2(-1/5) + z = 2
- 3/5 + 2/5 + z = 2
- 1/5 + z = 2
z = 2 + 1/5
z = 11/5

2) -2x + 3y + 4z = 12 |×1
3x + 4y - 2z = - 15 |×2
- 2x + 3y + 4z = 12
6x + 8y - 4z = - 30
----------------------------(+)
4x + 11y = - 18 ... pers 1
3x + 4y - 2z = - 15 |×3
5x + 6y - 3z = - 22 |×2
9x + 12y - 6z = -45
10x + 12y - 6z = - 66
------------------------------(-)
- x = 21
x = - 21 ... pers 2
pers 1 & 2
4x + 11y = - 18
4(-21) + 11y = - 18
- 84 + 11 y = - 18
11y = - 18 + 84
11y = 66
y = 6
-2x + 3y + 4z = 12
-2(-21) + 3(6) + 4z = 12
42 + 18 + 4z = 12
4z = 12 - 60
4z = - 48
z = (-12)