Răspunsuri

2014-10-15T21:46:04+03:00
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20
le aduni pe fiecare 
si dau 210

se calculeaza asa: 1+2+3+...+20= 20*(20+1) = 420
nu ca asta e gaus se face la inmultire
cum?
1+2+3+...+20
21+21+21+21+21+21+21+21+21+21=210
2014-10-15T21:47:14+03:00