Question

Ajutor,va rog!
Calculați:
a. 1/25+2/25+3/25+...+24/25

Answer 1

Salut,

$S=\dfrac{1}{25}+\dfrac{2}{25}+\dfrac{3}{25}+\ldots+\dfrac{24}{25}=\dfrac{1+2+3+\ldots+24}{25}=\\\\=\dfrac{\dfrac{24\cdot(24+1)}2}{25}=\dfrac{12\cdot 25}{25}=12,\ deci\ \boxed{S=12}.\\\\Am\ folosit\ formula\ sumei\ lui\ Gauss:\\\\1+2+3+\ldots+n=\dfrac{n(n+1)}2.$

Ai înțeles rezolvarea ?

Green eyes.

Answer 2

Răspuns:

Explicație pas cu pas: