yg bisa kasih full poin

dg cara gabungan

1) x - 3y = 0
2x + 3y = 12
------------------(+)
3x = 12
x = 4
disubtitusi ke pers :
x - 3y = 0
4 - 3y = 0
- 3y = - 4
y = 4/3
hp = { 4 , 4/3 }

2) 2x + y = 0 |×5
7x + 5y = 1
maka
10x + 5y = 0
7x + 5y = 1
------------------(-)
3x = - 1
x = - ⅓
disubtitusi ke pers :
2x + y = 0
2( - ⅓) + y = 0
- ⅔ + y = 0
y = ⅔
hp = ( - ⅓ , ⅔ )

3) 5x + y = 10 |×3
14x + 3y = 18
maka
15x + 3y = 30
14x + 3y = 18
---------------------(-)
x = 12
disubtitusi ke pers :
5x + y = 10
5(12) + y = 10
60 + y = 10
y = 10 - 60
y = -50
hp = ( 12 , -50}

4) x - 8y = - 20 |×5
5x - 7y = - 1
maka
5x - 40y = - 100
5x - 7y = - 1
-------------------------(-)
- 33 y = - 99
y = 3
disubtitusi ke pers :
x - 8y = - 20
x - 8(3) = - 20
x = - 20 + 24
x = 4
hp = ( 4 , 3 )