a) \(\dfrac{2007.2008-1}{2007.2008}\) và \(\dfrac{2008.2009-1}{2008.2009}\)
\(\dfrac{2007.2008-1}{2007.2008}=1+\dfrac{1}{2007.2008}\)
\(\dfrac{2008.2009-1}{2008.2009}=\dfrac{1}{2008.2009}\)
Vì \(\dfrac{1}{2007.2008}\)>\(\dfrac{1}{2008.2009}\) nên \(\dfrac{2007.2008-1}{2007.2008}\)>\(\dfrac{2008.2009-1}{2008.2009}\)