`1/2<4/5<5/6<6/7<7/8<8/9.`
`1/2=1−1/2`
`5/6=1−1/6`
`4/5=1−1/5`
`7/8=1−1/8`
`6/7=1−1/7`
`8/9=1−1/9`
Vì `1/2>1/5>1/6>1/7>1/8>1/9`
`⇒1−1/2<1−1/5<1−1/6<1−1/7<1−1/8<1−1/9`
`⇒1/2<4/5<5/6<6/7<7/8<8/9`
`#Neo`
\(\dfrac{1}{2};\dfrac{4}{5};\dfrac{5}{6};\dfrac{6}{7};\dfrac{7}{8};\dfrac{8}{9}\)