Question

CUM SE REZOLVA ACEASTA PROBLEMA DE MATEMATICA?
2+4+6+.....+100=?

Answer 1

$2+4+6+8+...+100=2(1+2+3+...+50)= 2*\frac{50*51}{2}=50*51$$=2550.$

Answer 2

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