`a) 2 |1/2 x - 1/3| - 3/2 = 1/4`
`⇒ 2|1/2 x - 1/3| = 1/4 + 3/2`
`⇒ 2|1/2 x - 1/3| = 7/4`
`⇒ |1/2 x - 1/3| = 7/4 : 2`
`⇒ |1/2 x - 1/3| = 7/4 . 1/2`
`⇒ |1/2 x - 1/3| = 7/8`
\(⇒ \left[ \begin{array}{l}\dfrac{1}{2}x - \dfrac{1}{3}= \dfrac{7}{8}\\\dfrac{1}{2}x - \dfrac{1}{3}=\dfrac{-7}{8}\end{array} \right.\)
\(⇒ \left[ \begin{array}{l}\dfrac{1}{2}x = \dfrac{7}{8} + \dfrac{1}{3}\\\dfrac{1}{2}x = \dfrac{-7}{8} + \dfrac{1}{3}\end{array} \right.\)
\(⇒ \left[ \begin{array}{l}\dfrac{1}{2} x=\dfrac{29}{24}\\\dfrac{1}{2}x =\dfrac{-13}{24} \end{array} \right.\)
\(⇒ \left[ \begin{array}{l}x=\dfrac{29}{12}\\x=\dfrac{-13}{12}\end{array} \right.\)
$\text{Vậy}$ `x ∈ {29/12; (-13)/12}`
`b) 4/5 - 1/2x = 1/10`
`⇒ 1/2x = 4/5 - 1/10`
`⇒ 1/2x = 7/10`
`⇒ x = 7/10 : 1/2`
`⇒ x = 7/10 . 2`
`⇒ x = 7/5`
