2) Ta có: `1/3 > 1/4 > 0`
`=> -1/3 < -1/4 < 0`
`=> -1/3 < -1/4 < 0 `
Lại có: `0 < 1/5 < 4/5`
`=> -1/3 < -1/4 < 0 < 1/5 < 4/5`
1)
Ta có:
\(-\dfrac{1}{2}=-\dfrac{15}{30};-\dfrac{1}{3}=-\dfrac{10}{30}\)
\(\Rightarrow\)Bốn số đó là:\(-\dfrac{11}{30};-\dfrac{12}{30};-\dfrac{13}{30};-\dfrac{14}{30}\)