Question

\(\dfrac{2006}{1.2}+\dfrac{2006}{2.3}+...+\dfrac{2006}{2006.2007}\)

Answer 1

Giúp mình với

 

Answer 2

\(N=\dfrac{2006}{1.2}+\dfrac{2006}{2.3}+...+\dfrac{2006}{2006.2007}\)

\(N.2006=\dfrac{2006}{1}-\dfrac{2006}{2}+\dfrac{2006}{2}-\dfrac{2006}{3}+...+\dfrac{2006}{2006}-\dfrac{2006}{2007}\)

\(N.2006=2006-\dfrac{2006}{2007}\)

\(N=2006-\dfrac{2006}{2007}:2006\)

\(N=2006-\dfrac{1}{2007}\)