Răspuns :
343.452+214.126+n=989.789
Calculam suma celor doua cunoscute.
557,578+n=989,789
Acum aflam necunoscuta
n=989,789-557.578
n=432,211
Calculam suma celor doua cunoscute.
557,578+n=989,789
Acum aflam necunoscuta
n=989,789-557.578
n=432,211