2kg m+5kg p=26
6kg m+7kg p=46 =>6kg m=46-7kg p
1)cat costa 2 kg mere?
2kg m=26-5kg p
2)cat costa 6 kg mere?
6kg m=3(26-5 p)=78-15 p
dar din relatia II avem 6kg m=46-7kg p
3)cat costa 1 kg pere?
46-7p=78-15 p
15 p-7 p=78-46
8 p=32
p=32:8
p=4 lei/kg
4)cat costa 1 kg mere?
2m=26-5x4
2m=26-20
2m=6 =>m=6:2
m =3 lei/kg