10>9
=>\(\dfrac{1}{10}< \dfrac{1}{9}\)
=>\(-\dfrac{1}{10}>-\dfrac{1}{9}\)
Ta có:
\(\dfrac{-1}{10}=\dfrac{\left(-1\right)\times9}{10\times9}=\dfrac{-9}{90}\)
\(\dfrac{-1}{9}=\dfrac{\left(-1\right)\times10}{9\times10}=\dfrac{-10}{90}\)
Vì \(9< 10\) nên \(\dfrac{-9}{90}>\dfrac{-10}{90}\)
hay \(\dfrac{-1}{10}>\dfrac{-1}{9}\)
Vì 10 < 9 thì quy ra
\(\dfrac{-1}{10}\) > \(\dfrac{-1}{9}\)
#ngocnhyy