Tìm x biết rằng: \( \displaystyle 3{2 \over 7}.x - {1 \over 8} = 2{3 \over 4}\)

* Hướng dẫn giải

Ta có:

 \(\begin{array}{l} 3\dfrac{2}{7}.x - \dfrac{1}{8} = 2\dfrac{3}{4}\\ 3\dfrac{2}{7}.x=2\dfrac{3}{4}+\dfrac{1}{8}\\ \dfrac{{23}}{7}x = \dfrac{{11}}{4}+\dfrac{1}{8} \\ \dfrac{{23}}{7}x = \dfrac{{23}}{8}\\ x = \dfrac{{23}}{8}:\dfrac{{23}}{7}\\ x = \dfrac{7}{8} \end{array}\)