Răspuns :
Notam acel numar cu x
x-11-12-13-14-15=1457
x-(11+12+13+14+15)=1457
x-65=1457 |+65
x=1522
x-11-12-13-14-15=1457
x-(11+12+13+14+15)=1457
x-65=1457 |+65
x=1522