\(1-\dfrac{2009}{2010}=\dfrac{1}{2010}\)
\(1-\dfrac{2010}{2011}=\dfrac{1}{2011}\)
\(\dfrac{1}{2010}>\dfrac{1}{2011}\Rightarrow\dfrac{2009}{2010}< \dfrac{2010}{2011}\)
\(\dfrac{2009}{2010}=1-\dfrac{1}{2010}< 1-\dfrac{1}{2011}=\dfrac{2010}{2011}\left(2010>2011\Rightarrow-\dfrac{1}{2010}< -\dfrac{1}{2011}\right)\)