1. Найдите произведение a) $$\frac{5}{6} \cdot \frac{7}{9}$$ б) $$\frac{3}{8} : \frac{9}{16}$$ в) $$1\frac{8}{25} \cdot \frac{4}{11}$$ г) $$3\frac{5}{7} \cdot 1\frac{1}{13}$$ д) $$\frac{15}{16} : 5$$

1. $$\frac{5}{6} \cdot \frac{7}{9} = \frac{35}{54}$$
2. $$\frac{3}{8} : \frac{9}{16} = \frac{3}{8} \cdot \frac{16}{9} = \frac{1}{1} \cdot \frac{2}{3} = \frac{2}{3}$$
3. $$1\frac{8}{25} \cdot \frac{4}{11} = \frac{33}{25} \cdot \frac{4}{11} = \frac{3 \cdot 11 \cdot 4}{25 \cdot 11} = \frac{12}{25}$$
4. $$3\frac{5}{7} \cdot 1\frac{1}{13} = \frac{26}{7} \cdot \frac{14}{13} = \frac{2 \cdot 13}{1} \cdot \frac{2 \cdot 7}{13} = 4$$
5. $$\frac{15}{16} : 5 = \frac{15}{16} \cdot \frac{1}{5} = \frac{3 \cdot 5 \cdot 1}{16 \cdot 5} = \frac{3}{16}$$

Ответ: a) $$\frac{35}{54}$$; б) $$\frac{2}{3}$$; в) $$\frac{12}{25}$$; г) 4; д) $$\frac{3}{16}$$