$c) \dfrac{4}{3}-\dfrac{1}{2}x=4$
$↔\dfrac{1}{2}x=\dfrac{4}{3}-4$
$↔\dfrac{1}{2}x=-\dfrac{8}{3}$
$↔x=\dfrac{-8}{3}:\dfrac{1}{2}$
$↔x=\dfrac{-8}{3}.2$
$↔x = \dfrac{-16}{3}$
$d) \dfrac{1}{2}-\dfrac{2}{3}:x=\dfrac{1}{5}$
$↔\dfrac{2}{3}:x=\dfrac{1}{2}-\dfrac{1}{5}$
$↔\dfrac{2}{3}:x=\dfrac{3}{10}$
$↔x=\dfrac{2}{3}:\dfrac{3}{10}$
$↔x=\dfrac{2}{3}.\dfrac{10}{3}$
$↔x=\dfrac{20}{9}$
