tolong jawab foto diatas yg jawab saya bakal doain agar tambah cerdik,pintar

susu = x
gelas = y

3x + 3y = 11700 |×2
4x + 2y = 9600 |×3

6x +6y = 23400
12x +6y = 28800
______________-
-6x = -5400
x = -5400/-6
x = 900

subtitusi persamaan x

3x +3y = 11700
3(900) +3y = 11700
3y = 11700 - 2700
3y = 9000
y = 9000/3
y = 3000

diketahui harga
susu = 900
gelas = 3000

harga 4 susu dan 5 gelas
= 4(900) + 5(3000)
= 3600 + 15000
= 18.600

semoga membantu