Răspuns :
S=10+11+12+......+73
S=73+72+71+......+10
__________________
2S=83+83+83+.....+83
2S=83×64
2S=5312
S=2656
S=73+72+71+......+10
__________________
2S=83+83+83+.....+83
2S=83×64
2S=5312
S=2656