\(\begin{array}{l}
\dfrac{3}{2} \times \dfrac{8}{{10}} - x = \dfrac{2}{4}\\
\dfrac{3}{2} \times \dfrac{4}{5} - x = \dfrac{1}{2}\\
\dfrac{{12}}{{10}} - x = \dfrac{1}{2}\\
x = \dfrac{{12}}{{10}} - \dfrac{1}{2}\\
x = \dfrac{{12}}{{10}} - \dfrac{5}{{10}}\\
x = \dfrac{7}{{10}}
\end{array}\)