Question

suma nr 3+7+11+15+...+47

Answer 1

   
[tex]\displaystyle\\ \text{Calculam numarul de numere:}\\\\ n = \frac{47-3}{4}+1= \frac{44}{4}+1 = 11+1=12~\text{numere}\\\\ \text{Aplicam formula lui Gauss:}\\\\ S = \frac{n(47+3)}{2}= \frac{12\times50}{2}=6\times 50 = \boxed{\bf 300}[/tex]