Question

Calculati suma: S=2+6+10+...+110

Answer 1

$S=(4*0+2)+(4*1+2)+....+(4*27+2)= \\ =4(0+1+2+3+...+27)+(2+2+2+...+2)(de\ 28\ ori\ 2) \\ =4* \frac{27*28}{2}+56= 1512+56=1568$

Answer 2

[tex]Suma~lui~Gauss:2+6+10+...+110\\ =\ \textgreater \ S=110*(110+1)/2\\ =\ \textgreater \ S=12.210/2\\ =\ \textgreater \ S=615[/tex]