Ta có :
$A = \dfrac{2010}{2011}+\dfrac{2011}{2012}+\dfrac{2012}{2010} $
$=1+1+1-\dfrac{1}{2011}-\dfrac{1}{2012}+\dfrac{2}{2010} > 3 $
$B = \dfrac{1}{4}+\dfrac{1}{3}+\dfrac{1}{5}+...+\dfrac{1}{17} < 13.\dfrac{1}{5}+\dfrac{1}{3}+\dfrac{1}{4} < 3$
Do đó : $A > B$