一、通分。
$\frac{5}{6}$和$\frac{7}{10}$ $\frac{5}{8}$和$\frac{17}{24}$ $\frac{8}{15}$和$\frac{13}{25}$
$\frac{5}{12}$和$\frac{7}{18}$ $\frac{3}{5}$和$\frac{11}{20}$ $\frac{3}{4}$和$\frac{5}{9}$
$\frac{3}{8}$和$\frac{23}{36}$ $\frac{7}{10}$和$\frac{5}{12}$ $\frac{5}{32}$和$\frac{9}{48}$
$\frac{3}{5}$和$\frac{5}{13}$ $\frac{25}{36}$和$\frac{13}{18}$ $\frac{7}{20}$和$\frac{2}{3}$
$\frac{4}{15}$和$\frac{7}{25}$ $\frac{2}{3}$和$\frac{19}{54}$ $\frac{7}{20}$和$\frac{2}{15}$

$\frac{5}{6}=\frac{25}{30}$ $\frac{7}{10}=\frac{21}{30}$
$\frac{5}{8}=\frac{15}{24}$ $\frac{17}{24}=\frac{17}{24}$
$\frac{8}{15}=\frac{40}{75}$ $\frac{13}{25}=\frac{39}{75}$
$\frac{5}{12}=\frac{15}{36}$ $\frac{7}{18}=\frac{14}{36}$
$\frac{3}{5}=\frac{12}{20}$ $\frac{11}{20}=\frac{11}{20}$
$\frac{3}{4}=\frac{27}{36}$ $\frac{5}{9}=\frac{20}{36}$
$\frac{3}{8}=\frac{27}{72}$ $\frac{23}{36}=\frac{46}{72}$
$\frac{7}{10}=\frac{42}{60}$ $\frac{5}{12}=\frac{25}{60}$
$\frac{5}{32}=\frac{15}{96}$ $\frac{9}{48}=\frac{18}{96}$
$\frac{3}{5}=\frac{39}{65}$ $\frac{5}{13}=\frac{25}{65}$
$\frac{25}{36}=\frac{25}{36}$ $\frac{13}{18}=\frac{26}{36}$
$\frac{7}{20}=\frac{21}{60}$ $\frac{2}{3}=\frac{40}{60}$
$\frac{4}{15}=\frac{20}{75}$ $\frac{7}{25}=\frac{21}{75}$
$\frac{2}{3}=\frac{36}{54}$ $\frac{19}{54}=\frac{19}{54}$
$\frac{7}{20}=\frac{21}{60}$ $\frac{2}{15}=\frac{8}{60}$