a)Có:
\(x=\dfrac{2006}{2007}+\dfrac{1}{2007}\)
\(y=\dfrac{2007}{2008}+\dfrac{1}{2008}\)
\(Có\) \(\dfrac{1}{2007}>\dfrac{1}{2008}\) nên \(\dfrac{2006}{2007}+\dfrac{1}{2007}\)\(>\)\(\dfrac{2007}{2008}+\dfrac{1}{2008}\)
\(\Rightarrow\)\(\dfrac{2006}{2007}>\dfrac{2007}{2008}\)