Ответ:

а) \(\frac{1}{11}-\frac{1}{33}=\frac{3-1}{33}=\frac{2}{33}\).

б) \(\frac{7}{11}-\frac{7}{12}=\frac{84-77}{132}=\frac{7}{132}\).

в) \(\frac{5}{9}-\frac{7}{18}=\frac{10-7}{18}=\frac{1}{6}\).

г) \(\frac{8}{21}-\frac{4}{35}=\frac{40-12}{105}=\frac{4}{15}\).

д) \(\frac{13}{30}-\frac{2}{45}=\frac{39-4}{90}=\frac{7}{18}\).

е) \(\frac{7}{15}-\frac{2}{5}=\frac{7-6}{15}=\frac{1}{15}\).

ж) \(\frac{4}{5}-\frac{5}{8}=\frac{32-25}{40}=\frac{7}{40}\).

з) \(\frac{7}{24}-\frac{5}{18}=\frac{21-20}{72}=\frac{1}{72}\).

и) \(\frac{13}{60}-\frac{7}{40}=\frac{26-21}{120}=\frac{1}{24}\).

к) \(\frac{11}{21}-\frac{3}{14}=\frac{22-9}{42}=\frac{13}{42}\).

л) \(\frac{11}{16}-\frac{5}{12}=\frac{33-20}{48}=\frac{13}{48}\).

м) \(\frac{11}{63}-\frac{5}{42}=\frac{22-15}{126}=\frac{1}{18}\).