Question

So sánh:

A= 2010/2011 - 2011/2012 + 2012/2013 - 2013/ 2014  và  B= 1/ 2010.2011 - 1/ 2012.2013

Answer 1

\(A=\left(1-\frac{1}{2011}\right)-\left(1-\frac{1}{2012}\right)+\left(1-\frac{1}{2013}\right)-\left(1-\frac{1}{2014}\right)\)

\(=1-\frac{1}{2011}-1+\frac{1}{2012}+1-\frac{1}{2013}-1+\frac{1}{2014}\)

\(=\left(1-1+1-1\right)-\left(\frac{1}{2011}+\frac{1}{2012}-\frac{1}{2013}+\frac{1}{2014}\right)\)

 

còn lại bó tay @@ 

Answer 2

\(A=\frac{2010}{2011}-\frac{2011}{2012}+\frac{2012}{2013}-\frac{2013}{2014}\)

và 

\(B=\frac{1}{2010.2011}-\frac{1}{2012.2013}\)