3) Выполните умножение и деление: а) 3/4 × 2/1; б) 6/8 × 8/3; в) 7/9 × 3/4; г) 9/10 : 5/3; д) 7/8 : 63/8; е) 1/9 : 3/6.

1. \(\frac{3}{4}\times\frac{2}{1}=\frac{6}{4}=\frac{3}{2}=1\frac{1}{2}\).
2. \(\frac{6}{8}\times\frac{8}{3}=\frac{6}{3}=2\).
3. \(\frac{7}{9}\times\frac{3}{4}=\frac{21}{36}=\frac{7}{12}\).
4. \(\frac{9}{10}:\frac{5}{3}=\frac{9}{10}\times\frac{3}{5}=\frac{27}{50}\).
5. \(\frac{7}{8}:\frac{63}{8}=\frac{7}{8}\times\frac{8}{63}=\frac{1}{9}\).
6. \(\frac{1}{9}:\frac{3}{6}=\frac{1}{9}\times\frac{6}{3}=\frac{2}{9}\).

Ответ: а) \(1\frac{1}{2}\); б) \(2\); в) \(\frac{7}{12}\); г) \(\frac{27}{50}\); д) \(\frac{1}{9}\); е) \(\frac{2}{9}\).