harga 8 potong kue dadar gulung dan 6 potong kue leker Rp 14.400,00. Harga 6 potong kue dadar gulung dan 5 potong kue leker Rp 11.200,200. Harga 5 potong kue d

misal
kue dadar gulung = x
kue leker = y

8x + 6y = 14.400 |×3
6x + 5y = 11.200 |×4
maka
24x + 18y = 43.200
24x + 20y = 44.800
-----------------------------(-)
- 2y = - 1.600
y = 800

subtitusi
8x + 6y = 14.400
8x + 6(800) = 14.400
8x + 4.800 = 14.400
8x = 14.400 - 4.800
8x = 9.600
x = 1.200

nilai 5x + 8y
= 5(1.200) + 8(800)
= 6.000 + 6.400
= 12.400