Đáp án:
$\begin{array}{l}
e)\dfrac{2}{9} - \dfrac{7}{8}.x = \dfrac{1}{3}\\
\Rightarrow \dfrac{7}{8}.x = \dfrac{2}{9} - \dfrac{1}{3}\\
\Rightarrow \dfrac{7}{8}.x = \dfrac{2}{9} - \dfrac{3}{9}\\
\Rightarrow \dfrac{7}{8}.x = \dfrac{{ - 1}}{9}\\
\Rightarrow x = \dfrac{{ - 1}}{9}:\dfrac{7}{8}\\
\Rightarrow x = \dfrac{{ - 1}}{9}.\dfrac{8}{7}\\
\Rightarrow x = \dfrac{{ - 8}}{{63}}\\
Vậy\,x = \dfrac{{ - 8}}{{63}}\\
k)2\dfrac{3}{5}\left( {x - \dfrac{5}{7}} \right) = \dfrac{{ - 22}}{5}\\
\Rightarrow \dfrac{{13}}{5}.\left( {x - \dfrac{5}{7}} \right) = \dfrac{{ - 22}}{5}\\
\Rightarrow x - \dfrac{5}{7} = \dfrac{{ - 22}}{5}.\dfrac{5}{{13}}\\
\Rightarrow x - \dfrac{5}{7} = \dfrac{{ - 22}}{{13}}\\
\Rightarrow x = \dfrac{{ - 22}}{{13}} + \dfrac{5}{7}\\
\Rightarrow x = \dfrac{{ - 22.7 + 5.13}}{{13.7}}\\
\Rightarrow x = \dfrac{{ - 89}}{{91}}\\
Vậy\,x = \dfrac{{ - 89}}{{91}}
\end{array}$
