Вычислите: а) 5/9 − 7/18; б) 8/21 − 4/35; в) 4/5 − 5/8; г) 7/24 − 5/18; д) 11/16 − 5/12; е) 11/63 − 5/42.

1. \(\frac{5}{9}-\frac{7}{18}=\frac{10}{18}-\frac{7}{18}=\frac{3}{18}=\frac{1}{6}\).
2. \(\frac{8}{21}-\frac{4}{35}=\frac{40}{105}-\frac{12}{105}=\frac{28}{105}=\frac{4}{15}\).
3. \(\frac{4}{5}-\frac{5}{8}=\frac{32}{40}-\frac{25}{40}=\frac{7}{40}\).
4. \(\frac{7}{24}-\frac{5}{18}=\frac{21}{72}-\frac{20}{72}=\frac{1}{72}\).
5. \(\frac{11}{16}-\frac{5}{12}=\frac{33}{48}-\frac{20}{48}=\frac{13}{48}\).
6. \(\frac{11}{63}-\frac{5}{42}=\frac{22}{126}-\frac{15}{126}=\frac{7}{126}=\frac{1}{18}\).

Ответ: а) \(\frac{1}{6}\); б) \(\frac{4}{15}\); в) \(\frac{7}{40}\); г) \(\frac{1}{72}\); д) \(\frac{13}{48}\); е) \(\frac{1}{18}\).