$\frac{2}{3}x = 1$
$x = 1 : \frac{2}{3}$
$x = \frac{3}{2} = 1\frac{1}{2}$

$5x = \frac{1}{6}$
$x = \frac{1}{6} : 5$
$x = \frac{1}{6} * \frac{1}{5}$
$x = \frac{1}{30}$

$4x = \frac{1}{4}$
$x = \frac{1}{4} : 4$
$x = \frac{1}{4} * \frac{1}{4}$
$x = \frac{1}{16}$

7x = 20
$x = \frac{20}{7}$
$x = 2\frac{6}{7}$