a: \(\dfrac{-18}{91}>\dfrac{-18}{90}=\dfrac{-1}{5}\)
\(\dfrac{-23}{114}< \dfrac{-23}{115}=\dfrac{-1}{5}\)
Do đó: \(\dfrac{-18}{91}>\dfrac{-23}{114}\)
b: \(\dfrac{-22}{35}=\dfrac{-3894}{6195}\)
\(\dfrac{-103}{177}=\dfrac{-103\cdot35}{177\cdot35}=\dfrac{-3605}{6195}\)
mà -3894<-3605
nên -22/35<-103/177