Đáp án:
Giải thích các bước giải:
`a)|x-5/3|<1/3`
`=>-1/3<x-5/3<1/3`
`=>-1/3+5/3<x<1/3+5/3`
`=>4/3<x<2`
`b)`
`|x+11/2|>|-5,5|`
`=>|x+11/2|>5,5`
`=>|x+11/2|>11/2`
`=>`\(\left[ \begin{array}{l}x+\dfrac{11}{2}>\dfrac{11}{2}\\x+\dfrac{11}{2}<-\dfrac{11}{2}\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x>0\\x<-11\end{array} \right.\)
`c)`
`2/5<|x-7/5|<3/5`
$\bullet$
`2/5<|x-7/5|`
`=>`\(\left[ \begin{array}{l}x-\dfrac{7}{5}>\dfrac{2}{5}\\x-\dfrac{7}{5}<-\dfrac{2}{5}\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x>\dfrac{9}{5}\\x<-1\end{array} \right.\)
$\bullet$
`|x-7/5|<3/5`
`=>-3/5<x-7/5<3/5`
`=>-3/5+7/5<x<3/5+7/5`
`=>4/5<x<2`
Từ hai điều kiện trên `=>9/5<x<2`
