nghịch dảo 2 p/s ta có:
\(\frac{2010}{2009}v\text{à}\frac{2011}{2010}\)
\(\frac{2010}{2009}=1\frac{1}{2009}\) ;\(\frac{2011}{2010}=1\frac{1}{2010}\)
vì \(\frac{1}{2009}>\frac{1}{2010}\)
=>\(\frac{2009}{2010}
1-\(\frac{2009}{2010}=\frac{2010}{2010}-\frac{2009}{2010}=\frac{1}{2010}\)
1-\(\frac{2010}{2011}=\frac{2011}{2011}-\frac{2010}{2011}=\frac{1}{2011}\)
Vì 2010 < 2011 nên \(\frac{1}{2010}>\frac{1}{2011}nên\frac{2009}{2010}>\frac{2010}{2011}\)
Vậy \(\frac{2009}{2010}>\frac{2010}{2011}\)