👤

Cine imi calculeaza suma :2+3+4+5+...+56 dau coroana

Răspuns :

2+3+4+5+...+56=(1+2+3+4+5+...+56)-1=56*57/2 -1=28*57-2=1596-1=1595
Facem prin suma lui Gauss!
Tn*Tn+1:2
56*57:2=1596-1
R: 1595