a) $\frac{2017}{2016}$ > $\frac{2016}{2016}$ = 1
$\frac{2017}{2018}$ < $\frac{2018}{2018}$ = 1
=> $\frac{2017}{2016}$ > $\frac{2017}{2018}$
b) $\frac{-83}{111}$ = $\frac{-249}{333}$
Vì -249 = -249 và 333 > 0 => $\frac{-249}{333}$ = $\frac{-249}{333}$
=> $\frac{-249}{333}$ = $\frac{-83}{111}$
Chúc học tốt!!!