a) \(-\dfrac{19}{49}=\dfrac{\left(-19\right).47}{49.47}=\dfrac{-893}{2303}\)
\(\dfrac{-23}{47}=\dfrac{\left(-23\right).49}{47.49}=\dfrac{-1127}{2303}\)
Do \(-893>-1127\Rightarrow\dfrac{-893}{2303}>\dfrac{-1127}{2303}\)
Vậy \(\dfrac{-19}{49}>\dfrac{-23}{47}\)
b) \(\dfrac{998}{555}=\dfrac{998.556}{555.556}=\dfrac{554888}{308580}\)
\(\dfrac{999}{556}=\dfrac{999.555}{556.555}=\dfrac{554445}{308580}\)
Do \(554888>554445\Rightarrow\dfrac{554888}{308580}>\dfrac{554445}{308580}\)
Vậy \(\dfrac{998}{555}>\dfrac{999}{556}\)
c) \(\dfrac{-315}{380}=\dfrac{\left(-315\right).381}{380.381}=\dfrac{-120015}{144780}\)
\(\dfrac{-316}{381}=\dfrac{\left(-316\right).380}{381.380}=\dfrac{-120080}{144780}\)
Do \(-120015>-120080\Rightarrow\dfrac{-120015}{144780}>\dfrac{-120080}{144780}\)
Vậy \(\dfrac{-315}{380}>\dfrac{-316}{381}\)
