ta có :
`4/5 -5/6= 24/30 - 25/30=-1/30`
`1/3 - 3/10 = 10/30 - 9/30=1/30`
mà `-1/30 <= x/30 <= 1/30`
`=>x= -1;0;1`
`4/5-5/6≤ x/30 ≤ 1/3 - 3/10`
`24/30 - 25/30 ≤ x/30 ≤10/30 - 9/30`
`-1/30 ≤ x/30 ≤ 1/30`
`-1≤x≤1`
`=> x∈ {-1;0;1}`
\(-\dfrac{1}{30}\le\dfrac{x}{30}\le\dfrac{1}{30}\Rightarrow-1\le x\le1\Rightarrow x=-1;0;1\)
a)\(\dfrac{4}{5}-\dfrac{5}{6}\le\dfrac{x}{30}\le\dfrac{1}{3}-\dfrac{3}{10}\)
\(\Rightarrow\dfrac{24-25}{30}\le\dfrac{x}{30}\le\dfrac{10-9}{30}\)
\(\Rightarrow-\dfrac{1}{30}\le\dfrac{x}{30}\le\dfrac{1}{30}\)
\(\Rightarrow x=0\)
