prima:
a+b+c=1758
a-207=b-68=c-220
le aflam pe toate in functie de b
a-207=b-68
a=b-68+207
b ramane asa
c-220=b-68
c=b-68+220
inlocuim
b-68+207+b+b-68+220=1758
b+b+b-68+207-68+220=1758
3b+291=1758
3b=1467
b=489
acum pur si simplu inlocuim:
a=489-68+220
a=628
c=b-68+220
c=489-68+220
c=641