`\text{b)}`
`|x-2/7| = 3/5`
`=>` \(\left[ \begin{array}{l}x-\dfrac{2}{7} = \dfrac{3}{5}\\x-\dfrac{2}{7} = \dfrac{-3}{5}\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x= \dfrac{31}{35}\\x = \dfrac{-11}{35}\end{array} \right.\)
Vậy `x \in { 31/35 ; {-11}/35}`
`\text{c)}`
`1/9= {x+5}/27`
`=> 9(x+5) = 27`
`=> 9x + 45 = 27`
`=> 9x =-18`
`=> x = -2`