$\frac{8}{10} = \frac{2 * 4}{2 * 5} = \frac{4}{5}$
$\frac{4}{6} = \frac{2 * 2}{2 * 3} = \frac{2}{3}$
$\frac{6}{9} = \frac{3 * 2}{3 * 3} = \frac{2}{3}$
$\frac{10}{25} = \frac{5 * 2}{5 * 5} = \frac{2}{5}$
$\frac{14}{49} = \frac{7 * 2}{7 * 7} = \frac{2}{7}$
$\frac{5}{15} = \frac{5 * 1}{5 * 3} = \frac{1}{3}$
$\frac{12}{15} = \frac{3 * 4}{3 * 5} = \frac{4}{5}$
$\frac{14}{18} = \frac{2 * 7}{2 * 9} = \frac{7}{9}$