15kg cartofi........12kg varza........69 lei
5kg cartofi.........7kg varza.........29 lei /x3
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15c+12v=69
15c+21v=87
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//9v=18
1 kg varza=18:9
1 kg varza=2 lei
15c+12x2=69
15c+24=69
15c=45
1 kg de cartofi=3 lei
15x3+12x2=45+24=69