Ответ:

Чтобы разделить дробь на дробь, умножаем первую дробь на дробь, обратную второй.

  1. \(\frac{9}{8}:\frac{3}{4}=\frac{9}{8}\cdot\frac{4}{3}=\frac{3}{2}\).
  2. \(\frac{1}{2}:\frac{3}{5}=\frac{1}{2}\cdot\frac{5}{3}=\frac{5}{6}\).
  3. \(\frac{7}{10}:\frac{2}{9}=\frac{7}{10}\cdot\frac{9}{2}=\frac{63}{20}=3\frac{3}{20}\).
  4. \(\frac{1}{12}:\frac{1}{5}=\frac{1}{12}\cdot5=\frac{5}{12}\).
  5. \(\frac{5}{9}:\frac{1}{2}=\frac{5}{9}\cdot2=\frac{10}{9}=1\frac{1}{9}\).
  6. \(\frac{1}{3}:\frac{1}{6}=\frac{1}{3}\cdot6=2\).
  7. \(\frac{7}{16}:\frac{21}{32}=\frac{7}{16}\cdot\frac{32}{21}=\frac{2}{3}\).
  8. \(\frac{25}{27}:\frac{5}{9}=\frac{25}{27}\cdot\frac{9}{5}=\frac{5}{3}=1\frac{2}{3}\).
  9. \(\frac{6}{5}:\frac{10}{9}=\frac{6}{5}\cdot\frac{9}{10}=\frac{27}{25}=1\frac{2}{25}\).
  10. \(\frac{2}{5}:\frac{1}{10}=\frac{2}{5}\cdot10=4\).
  11. \(\frac{81}{161}:\frac{3}{46}=\frac{81}{161}\cdot\frac{46}{3}=\frac{54}{7}=7\frac{5}{7}\).
  12. \(\frac{5}{121}:\frac{25}{11}=\frac{5}{121}\cdot\frac{11}{25}=\frac{1}{55}\).

Ответ: а) \(\frac{3}{2}\); б) \(\frac{5}{6}\); в) \(3\frac{3}{20}\); г) \(\frac{5}{12}\); д) \(1\frac{1}{9}\); е) \(2\); ж) \(\frac{2}{3}\); з) \(1\frac{2}{3}\); и) \(1\frac{2}{25}\); к) \(4\); л) \(7\frac{5}{7}\); м) \(\frac{1}{55}\).