Ответ:

  1. \(\frac{5}{9}-\frac{4}{12}=\frac{20}{36}-\frac{12}{36}=\frac{8}{36}=\frac{2}{9}\).
  2. \(\frac{1}{3}-\frac{1}{7}=\frac{7}{21}-\frac{3}{21}=\frac{4}{21}\).
  3. \(\frac{13}{22}-\frac{14}{33}=\frac{39}{66}-\frac{28}{66}=\frac{11}{66}=\frac{1}{6}\).
  4. \(\frac{9}{10}-\frac{2}{15}=\frac{27}{30}-\frac{4}{30}=\frac{23}{30}\).