Bạn tham khảo :
$C1$
Ta có :
$1 - \dfrac{2020}{2010}= \dfrac{2010}{2010} - \dfrac{2020}{2010} = \dfrac{-10}{2010}$
$1-\dfrac{2021}{2011} = \dfrac{2011}{2011} -\dfrac{2021}{2011}= \dfrac{-10}{2011}$
Vì $\dfrac{-10}{2010} > \dfrac{-10}{2011} ⇒ \dfrac{2020}{2010} > \dfrac{2021}{2011}$
$C2$
Ta có :
$ \dfrac{2020}{2010} -1 = \dfrac{10}{2010}$
$ \dfrac{2021}{2011}-1 = \dfrac{10}{2011}$
Vì $ \dfrac{10}{2010} > \dfrac{10}{2011} ⇒ \dfrac{2010}{2020} > \dfrac{2021}{2011}$
