7kg mer+9 kgpere=41 lei
7kg mere+4 kgpere=26 lei scazand cele 2 operatii obsevam ca
5kg pere=15 lei
1kg pere=15/5=3lei
7kg mere+4x3lei=26 lei
7kg mere=26-12 lei
7 kg mere=14lei
1kg mere=14/7=2 lei
2).1 tona =1000kg
1q =100kg
1000-95x10=50kg
100kg-5x10=50 kg deci de 10 ori