7 lazi mere..................5 lazi pere......................600 kg
7 lazi mere................12 lazi pere......................901 kg
---------------------------------------------------------------------------------
// 7 lazi pere-------------------301 kg
1 lada pere=301:7
1 lada pere=43 kg
7 lazi mere+5x43=600
7 lazi mere+215=600
7 lazi mere=600-215
7 lazi mere=385
1 lada mere=385:7
1 lada mere=55 kg
proba: 7x55+5x43=385+215=600