jawaban dan cara nyaaaaaaaa

maaf cuma bisa bantu yang no.4 aja

4x + 2y = 14 |×2
x - 4y = - 10
maka
8x + 4y = 28
x - 4y = - 10
-------------------(+)
9x = 18
x = 2

subtitusi
x - 4y = - 10
2 - 4y = - 10
- 4y = - 10 + 2
- 4y = - 8
y = 2

hp = ( 2,2 )


5) x + y - z = 4
2x - y + z = 5
---------------------(+)
3x = 9
x = 3

subtitusi
x + 2y - 3z = 4
2x - y + z = 5 |×3
maka
x + 2y - 3z = 4
6x - 3y + 3z = 15
------------------------( + )
7x - y = 19
7(3) - y = 19
21 - y = 19
- y = 19 - 21
- y = - 2
y = 2

subtitusi
x + y - z = 4
3 + 2 - z = 4
5 - z = 4
- z = 4 - 5
- z = - 1
z = 1

hp = ( 3,2,1 )