Question

CINE STIE SA IMI REZOLVE SI MIE ACEASTA PROBLEMA VA ROG? 2+4+6+...+100=?

Answer 1

2+4+6+...+100=
2(1+2+3+...+50)=
Aplici Suma lui Gauss S=n(n+1)/2
n=nr. de termeni
S=50x51/2
S=25x51
S=1275
2x1275=2550

Answer 2

$\displaystyle 2+4+6+...+100=2(1+2+3+...+50)=2 \times \frac{50(50+1)}{2} = \\ \\ =2 \times \frac{50 \times 51}{2} =\not2 \times \frac{2550}{\not2} =2550$