Question

2+4+6+...+60 daca puteti si sa explicati

Answer 1

$2+4+6+...+60=2(1+2+3+...+30)=2* \frac{30*31}{2}=30*31=930$

Answer 2

$\displaystyle 2+4+6+...+60=2(1+2+3+...+30)=2 \times \frac{30(30+1)}{2} = \\ \\ =2 \times \frac{30 \times 31}{2} =\not 2 \times \frac{930}{\not 2} =930$