prima srea=a, a doua sera =b, a treia sera =c, a patra sera=d
a+b+c+d=2452kg cirese
a+b+c+400=d
a=b=c => 3a+d=2452kg cirese
3a+400=d
3a+3a+400=2452 kg cirese
6a+400=2452kg cirese
6a=2452-400=2052kg cirese
a=2052:6=342 =>b=342 c=342
d=342x3+400
d=1026+400=1426 kg cirese
