a) $\frac{3}{5}$ = $\frac{6}{10}$; $2$ = $\frac{20}{10}$
b) $\frac{15}{18}$ < $1$
$\frac{3}{5}$ < $\frac{9}{5}$
$\frac{13}{11}$ > $\frac{13}{23}$
$\frac{7}{10}$ > $\frac{2}{5}$
$\frac{3}{7}$ < $\frac{4}{7}$
$1$ < $\frac{101}{100}$
$\frac{2}{9}$ = $\frac{20}{90}$
$\frac{19}{12}$ < $\frac{19}{9}$