Вычислите: а) 3/4 · 5/7; б) 4/11 · 3/4; в) 5/7 · 14/19; г) (3/5)²; д) 4/5 : 3/7; е) 15/8 : 5/4; ж) 4/9 : 2; з) 6 : 3/5.

1. \(\frac{3}{4}\cdot\frac{5}{7}=\frac{15}{28}\).
2. \(\frac{4}{11}\cdot\frac{3}{4}=\frac{3}{11}\).
3. \(\frac{5}{7}\cdot\frac{14}{19}=\frac{10}{19}\).
4. \(\left(\frac{3}{5}\right)^2=\frac{9}{25}\).
5. \(\frac{4}{5}:\frac{3}{7}=\frac{4}{5}\cdot\frac{7}{3}=\frac{28}{15}\).
6. \(\frac{15}{8}:\frac{5}{4}=\frac{15}{8}\cdot\frac{4}{5}=\frac{3}{2}\).
7. \(\frac{4}{9}:2=\frac{4}{9}\cdot\frac{1}{2}=\frac{2}{9}\).
8. \(6:\frac{3}{5}=6\cdot\frac{5}{3}=10\).

Ответ: а) \(\frac{15}{28}\); б) \(\frac{3}{11}\); в) \(\frac{10}{19}\); г) \(\frac{9}{25}\); д) \(\frac{28}{15}\); е) \(\frac{3}{2}\); ж) \(\frac{2}{9}\); з) \(10\).