Tolong.................

5X + 4Y = 20000000 (i)

5(10/100 . X) + 4(15/100 . Y) = 2500000
---> 50X + 60Y = 250000000
---> 5X + 6Y = 25000000 (ii)

(ii) - (i)
2Y = 5000000
Y = 2500000

Harga jual Y
115/100 × 2500000 = Rp2.875.000