`\text{a)}`
`x +3/4 = {-1}/12`
`-> x = {-1}/12 -3/4`
`-> x = {-1}/12 - 9/12`
`-> x = {-5}/6`
Vậy `x = {-5}/6`
`\text{b)}`
`|3/8-x| =5/6`
`->` \(\left[ \begin{array}{l}\dfrac{3}{8}- x = \dfrac{5}{6}\\\dfrac{3}{8}- x = \dfrac{-5}{6}\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x= \dfrac{-11}{24}\\x= \dfrac{29}{24}\end{array} \right.\)
Vậy `x \in { {-11}/24 ; 29/24 }`
`\text{c)}`
`x +5/6 = {-2}/3`
`-> x = {-2}/3 - 5/6`
`-> x = {-3}/2`
Vậy `x = {-3}/2`
`\text{d)}`
`{-3}/4 : (2 1/4x - 25% ) =3`
`-> {-3}/4 : ( 9/4x - 1/4 ) =3`
`-> 9/4x - 1/4 = {-3}/4 . 1/3`
`-> 9/4x -1/4 = {-1}/4`
`-> 9/4x =0`
`-> x =0`
Vậy `x =0`
