a=lei/to zahar
b=lei/to faina
350a+180b=1940000 35a+18b=194000
160a+280b=1480000 4a+7b=37000
b=(37000-4a)/7
35a+18(37000-4a)/7=194000
245a+666000-72a=1358000
173a=692000
a=4000 lei/ tona zahar
b=(37000-4×4000)/7=(37000-16000)/7=3000 lei/to faina
3 tone zahar=3×4000=12000 lei
5 tone faina=5×3000=15000 lei
12000:15000=0,8=80%
