tolomh jawabin pake cara ya besok dikumpul

1) 2x - y = 18
- y = - 2x + 18
y = 2x - 18
subtitusi ke pers :
3x + 4y = 5
3x + 4(2x - 18) = 5
3x + 8x - 72 = 5
11x = 5 + 72
11x = 77
x = 7
subtitusi ke pers :
y = 2x - 18
y = 2(7) - 18
y = 14 - 18
y = - 4
hp = ( 7,-4 )

3) 4x - 3y = 15 |×3
6x + 9y = 9
maka
12x - 9y = 45
6x + 9y = 9
---------------------(+)
18x = 54
x = 3
• 4x - 3y = 15 |×3
6x + 9y = 9 |×2
maka
12x - 9y = 45
12x + 18y = 18
--------------------(-)
- 27y = 27
y = - 1
hp = ( 3 , - 1 )