Tìm \(x\), biết: + = -

* Hướng dẫn giải

\(\begin{array}{l}\,\dfrac{2}{3} + \dfrac{3}{4}x =  - \dfrac{5}{6}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\dfrac{3}{4}x =  - \dfrac{5}{6} - \dfrac{2}{3}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\dfrac{3}{4}x = \dfrac{{ - 3}}{2}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = \dfrac{{ - 3}}{2}:\dfrac{3}{4}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = \dfrac{{ - 3}}{2}.\dfrac{4}{3}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x =  - 2\end{array}\)