bantuin jawab soal yg ada digambar. pliss

7) x = 4y
subtitusi ke pers :
2x + 5y = 39
2(4y) + 5y = 39
8y + 5y = 39
13y = 39
y = 3

8) x = 3y
subtitusi ke pers :
x + 4y = 14
3y + 4y = 14
7y = 14
y = 2
subtitusi
x = 3y
x = 3(2)
x = 6

9) x = 2y
subtitusi ke pers :
x + 3y = 20
2y + 3y = 20
5y = 20
y = 4
subtitusi ke pers :
x = 2y
x = 2(4)
x = 8
hp = ( 8,4 )

10) 2p + q = 9
p - 3q = 8 |×2
maka
2p + q = 9
2p - 6q = 16
-----------------(-)
7q = - 7
q = - 1

11) 3p + q + 10 = 0
3p + q = - 10
2p + 3q + 16 = 0
2p + 3q = - 16
jadi
3p + q = - 10 |×2
2p + 3q = - 16 |×3
maka
6p + 2q = - 20
6p + 9q = - 48
---------------------(-)
- 7q = 28
q = - 4
subtitusi
2p + q = - 10
2p - 4 = - 10
2p = 10 + 4
2p = 14
p = 7

12) 2a - b = - 1 |×2
3a + 2b = 16
maka
4a - 2b = - 2
3a + 2b = 16
-------------------(+)
7a = 14
a = 2
subtitusi
2a - b = - 1
2(2) - b = - 1
4 - b = - 1
- b = - 1 - 4
- b = - 5
b = 5
hp = ( 2,5 )

7) x = 4y
subtitusi ke pers :
2x + 5y = 39
2(4y) + 5y = 39
8y + 5y = 39
13y = 39
y = 3

8) x = 3y
subtitusi ke pers :
x + 4y = 14
3y + 4y = 14
7y = 14
y = 2
subtitusi
x = 3y
x = 3(2)
x = 6

9) x = 2y
subtitusi ke pers :
x + 3y = 20
2y + 3y = 20
5y = 20
y = 4
subtitusi ke pers :
x = 2y
x = 2(4)
x = 8
hp = ( 8,4 )

10) 2p + q = 9
p - 3q = 8 |×2
maka
2p + q = 9
2p - 6q = 16
-----------------(-)
7q = - 7
q = - 1

11) 3p + q + 10 = 0
3p + q = - 10
2p + 3q + 16 = 0
2p + 3q = - 16
jadi
3p + q = - 10 |×2
2p + 3q = - 16 |×3
maka
6p + 2q = - 20
6p + 9q = - 48
---------------------(-)
- 7q = 28
q = - 4
subtitusi
2p + q = - 10
2p - 4 = - 10
2p = 10 + 4
2p = 14
p = 7

12) 2a - b = - 1 |×2
3a + 2b = 16
maka
4a - 2b = - 2
3a + 2b = 16
-------------------(+)
7a = 14
a = 2
subtitusi
2a - b = - 1
2(2) - b = - 1
4 - b = - 1
- b = - 1 - 4
- b = - 5
b = 5
hp = ( 2,5