Cat face 21+22+.....100?
E super urgent


Răspuns :

Completezi   o   suma   gaus   adaugand   si   scazina   1+2+,,,+20
1+2+....+20+21+22+...++100=suma   gaus=100*101/2=5050
1+2+....+20=suma  gauss=20*21/2=210
s=5050-210=4840