Question

calculati
2+4+6+.........+100=

Answer 1

2+4+6+...+100=2(1+2+...+50)=2×50×51÷2=50×51=2550

Answer 2

$1+2+3+...+n= \frac{n(n+1)}{2}$

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