notam: a=mingi rosii
b=mingi verzi
c=mingi galbene
675= b +c ; b=675-c
753=a +c ; c=753-a
572=a +b
inlocuim :
572=a+675-c
572+c=a+675
572+753-a=a+675
2a=1325-675
2a=650
a=650:2
a=325mingi rosii
c=753-a
c=753-325
c=428mingi galbene
b=675-c
b=675-428
b=247 mingi verzi