Răspuns :
Notam cele trei numere cu a,b si c.
a+b+c=868
a+b=637
b+c=391
637+c=868
c=868-637
c=231
a+391=868
a=868-391
a=477
b+231=391
b=391-231
b=160
Verificare:
477+160+231=868
a+b+c=868
a+b=637
b+c=391
637+c=868
c=868-637
c=231
a+391=868
a=868-391
a=477
b+231=391
b=391-231
b=160
Verificare:
477+160+231=868
a+b+c=868
a+b=637
b+c=391
637+c=868
c=868-637
c=231
a+391=868
a=868-391
a=477
b+231=391
b=391-231
b=160
a+b=637
b+c=391
637+c=868
c=868-637
c=231
a+391=868
a=868-391
a=477
b+231=391
b=391-231
b=160