`a) x - 5/6 = -7/6`
` x = -7/6 + 5/6`
` x = -2/6 = -1/3`
Vậy `x = -1/3`
`b) 4/3 - 7/12 : x = 1/6`
` 7/12 : x = 4/3 - 1/6`
` 7/12 : x = 7/6`
` x = 7/12 : 7/6`
` x = 1/2`
Vậy `x = 1/2`
`c) (2x - 3)^2 - 5 = 4`
` (2x - 3)^2 = 4 + 5`
` (2x - 3)^2 = 9`
`=>(2x - 3)^2 = 3^2`
`=> 2x - 3 = 3`
`=> 2x = 3 + 3`
`=> 2x = 6`
`=> x = 6 : 2`
`=> x = 3`
Vậy `x = 3`
`d) 1/3 - |x + 3/4| = -2/3`
` |x + 3/4|= 1/3 - (-2/3)`
`|x + 3/4|= 1`
`=>`\(\left[ \begin{array}{l}x + \dfrac{3}{4} = 1\\x + \dfrac{3}{4} = -1\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x = 1 - \dfrac{3}{4}\\x = (-1) - \dfrac{3}{4}\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=\dfrac{1}{4}\\x=-\dfrac{7}{4}\end{array} \right.\)
Vậy `x ∈ {1/4 ; -7/4}`
