`text{Đáp án + Giải thích các bước giải}`
`a)`
`3/4-5/6 . x=2`
`=>5/6 . x=3/4-2`
`=>5/6 . x=-5/4`
`=>x=-5/4 : 5/6`
`=>x=-3/2`
Vậy `x=-3/2`
`b)`
`|3.x-2|=3/4`
`=>`$\left[\begin{array}{l}3x-2=\dfrac{3}{4}\\3x-2=-\dfrac{3}{4}\end{array}\right.$
`=>`$\left[\begin{array}{l}3x=\dfrac{3}{4}+2\\3x=-\dfrac{3}{4}+2\end{array}\right.$
`=>`$\left[\begin{array}{l}3x=\dfrac{11}{4}\\3x=\dfrac{5}{4}\end{array}\right.$
`=>`$\left[\begin{array}{l}x=\dfrac{11}{12}\\x=\dfrac{5}{12}\end{array}\right.$
Vậy `x \in {11/12 ; 5/12}`
