$\frac{3\frac{9}{14}}{2\frac{1}{7}} = \frac{х}{1,5}$
$х = 3\frac{9}{14} * 1\frac{1}{2} : 2\frac{1}{7}$
$х = \frac{51}{14} * \frac{3}{2} * \frac{7}{15}$
$х = \frac{51}{2} * \frac{1}{2} * \frac{1}{5}$
$х = \frac{51}{20} = \frac{25,5}{10} = 2,55$

$\frac{2\frac{8}{15}}{3\frac{4}{5}} = \frac{1,5}{z}$
$z = 3\frac{4}{5} * 1,5 : 2\frac{8}{15}$
$z = \frac{19}{5} * \frac{3}{2} * \frac{15}{38}$
$z = \frac{1}{1} * \frac{3}{2} * \frac{3}{2}$
$z = \frac{9}{4} = \frac{225}{100} = 2,25$