500gfaina+80g unt+100g zahar+50g cacao=730g aluatul
730g--------2 oua
x------------9 oua
x=(9·730)/2
x=3285g aluatul
730g----------500g faina
3285g--------x
x=(3285·500)/730
x=2250g faina
730g---------80g unt
3285---------x
x=(80·3285)/730
x=360g unt
730---------100g zahar
3285-------x
x=(3285·100)/730
x=450g zahar
730g=======50g cacau
3285g----------x
x=(3285·50)/730
x=225 g cacao
R pt.9 oua se folosesc 225g cacao, 450g zahar, 360g unt, 2250g faina