3r + 1cast + 2c = 15
1r + 1cast + 1c = 8
2r + 1cast + 1 c = 11
scadem ultimele doua ecuatii
1r = 3 lei kg de rosii
scadem primele doua ecuatii
2r + 1c = 7
inlocuim r cu 3
2 * 3 + 1c = 7
1c = 7 - 6
c = 1 lei kg de cartofi
3 + 1cast + 1 = 8
1cast = 8 - 4
castraveti = 4 lei kg