$\frac{2 * 3}{4 * 5} = \frac{1 * 3}{2 * 5} = \frac{3}{10}$;
$\frac{2 * 3}{7 * 2} = \frac{1 * 3}{7 * 1} = \frac{3}{7}$;
$\frac{5 * 4}{4 * 9} = \frac{5 * 1}{1 * 9} = \frac{5}{9}$;
$\frac{7 * 5}{2 * 7} = \frac{1 * 5}{2 * 1} = \frac{5}{2}$.

$\frac{4 * 5}{3 * 6} = \frac{2 * 5}{3 * 3} = \frac{10}{9}$;
$\frac{15 * 3}{11 * 10} = \frac{3 * 3}{11 * 2} = \frac{9}{22}$;
$\frac{14 * 9}{15 * 7} = \frac{2 * 3}{5 * 1} = \frac{6}{5}$;
$\frac{2 * 3}{9 * 8} = \frac{1 * 1}{3 * 4} = \frac{1}{12}$.