② І Найдите значение выражения: 1) $$3 \frac{3}{4}: \frac{3}{8}: 1 \frac{1}{4}$$; 3) $$1 \frac{4}{9} \cdot \frac{15}{32}: 1 \frac{19}{36}$$; 5) $$3 \frac{4}{7}: 1 \frac{1}{7} \cdot \frac{2}{3}$$; 8) $$\frac{5}{12}+ \frac{1}{8}: \frac{3}{8}$$; 9) $$2 \frac{6}{7}: (\frac{5}{6} - \frac{9}{14})$$; 10) $$2 \frac{6}{7}: \frac{5}{6} - \frac{9}{14}$$; 2) $$3 \frac{3}{4}: (\frac{3}{8}: 1 \frac{1}{4})$$ 4) $$1 \frac{7}{9} \cdot (\frac{15}{32}: 1 \frac{19}{36})$$ 6) $$3 \frac{4}{7}: (1 \frac{1}{7} \cdot \frac{2}{3}): (\frac{5}{12}+ \frac{1}{8}): \frac{3}{8}$$

Решим примеры:

1. $$3 \frac{3}{4}: \frac{3}{8}: 1 \frac{1}{4} = \frac{15}{4} : \frac{3}{8} : \frac{5}{4} = \frac{15}{4} \cdot \frac{8}{3} \cdot \frac{4}{5} = \frac{15 \cdot 8 \cdot 4}{4 \cdot 3 \cdot 5} = \frac{3 \cdot 5 \cdot 8 \cdot 4}{4 \cdot 3 \cdot 5} = 8$$
2. $$3 \frac{3}{4}: (\frac{3}{8}: 1 \frac{1}{4}) = \frac{15}{4} : (\frac{3}{8} : \frac{5}{4}) = \frac{15}{4} : (\frac{3}{8} \cdot \frac{4}{5}) = \frac{15}{4} : \frac{3 \cdot 4}{8 \cdot 5} = \frac{15}{4} : \frac{3}{10} = \frac{15}{4} \cdot \frac{10}{3} = \frac{15 \cdot 10}{4 \cdot 3} = \frac{5 \cdot 3 \cdot 2 \cdot 5}{2 \cdot 2 \cdot 3} = \frac{25}{2} = 12 \frac{1}{2}$$
3. $$1 \frac{4}{9} \cdot \frac{15}{32}: 1 \frac{19}{36} = \frac{13}{9} \cdot \frac{15}{32}: \frac{55}{36} = \frac{13}{9} \cdot \frac{15}{32} \cdot \frac{36}{55} = \frac{13 \cdot 15 \cdot 36}{9 \cdot 32 \cdot 55} = \frac{13 \cdot 3 \cdot 5 \cdot 4 \cdot 9}{9 \cdot 4 \cdot 8 \cdot 5 \cdot 11} = \frac{13 \cdot 3}{8 \cdot 11} = \frac{39}{88}$$
4. $$1 \frac{7}{9} \cdot (\frac{15}{32}: 1 \frac{19}{36}) = \frac{16}{9} \cdot (\frac{15}{32}: \frac{55}{36}) = \frac{16}{9} \cdot (\frac{15}{32} \cdot \frac{36}{55}) = \frac{16}{9} \cdot \frac{15 \cdot 36}{32 \cdot 55} = \frac{16 \cdot 15 \cdot 36}{9 \cdot 32 \cdot 55} = \frac{16 \cdot 3 \cdot 5 \cdot 4 \cdot 9}{9 \cdot 16 \cdot 2 \cdot 5 \cdot 11} = \frac{3 \cdot 4}{2 \cdot 11} = \frac{12}{22} = \frac{6}{11}$$
5. $$3 \frac{4}{7}: 1 \frac{1}{7} \cdot \frac{2}{3} = \frac{25}{7} : \frac{8}{7} \cdot \frac{2}{3} = \frac{25}{7} \cdot \frac{7}{8} \cdot \frac{2}{3} = \frac{25 \cdot 7 \cdot 2}{7 \cdot 8 \cdot 3} = \frac{25 \cdot 2}{8 \cdot 3} = \frac{25}{4 \cdot 3} = \frac{25}{12} = 2 \frac{1}{12}$$
6. $$3 \frac{4}{7}: (1 \frac{1}{7} \cdot \frac{2}{3}): (\frac{5}{12}+ \frac{1}{8}): \frac{3}{8} = \frac{25}{7} : (\frac{8}{7} \cdot \frac{2}{3}): (\frac{5}{12}+ \frac{1}{8}): \frac{3}{8} = \frac{25}{7} : \frac{16}{21} : (\frac{10}{24}+ \frac{3}{24}): \frac{3}{8} = \frac{25}{7} : \frac{16}{21}: \frac{13}{24}: \frac{3}{8} = \frac{25}{7} \cdot \frac{21}{16} \cdot \frac{24}{13} \cdot \frac{8}{3} = \frac{25 \cdot 21 \cdot 24 \cdot 8}{7 \cdot 16 \cdot 13 \cdot 3} = \frac{25 \cdot 3 \cdot 7 \cdot 3 \cdot 8 \cdot 8}{7 \cdot 2 \cdot 8 \cdot 13 \cdot 3} = \frac{25 \cdot 3 \cdot 8}{2 \cdot 13} = \frac{25 \cdot 3 \cdot 4}{13} = \frac{300}{13} = 23 \frac{1}{13}$$
7. $$\frac{5}{12}+ \frac{1}{8}: \frac{3}{8} = \frac{5}{12} + \frac{1}{8} \cdot \frac{8}{3} = \frac{5}{12} + \frac{1}{3} = \frac{5}{12} + \frac{4}{12} = \frac{9}{12} = \frac{3}{4}$$
8. $$2 \frac{6}{7}: (\frac{5}{6} - \frac{9}{14}) = \frac{20}{7}: (\frac{5 \cdot 7}{6 \cdot 7} - \frac{9 \cdot 3}{14 \cdot 3}) = \frac{20}{7} : (\frac{35}{42} - \frac{27}{42}) = \frac{20}{7} : \frac{8}{42} = \frac{20}{7} \cdot \frac{42}{8} = \frac{20 \cdot 42}{7 \cdot 8} = \frac{20 \cdot 6}{8} = \frac{5 \cdot 4 \cdot 6}{2 \cdot 4} = \frac{5 \cdot 6}{2} = 5 \cdot 3 = 15$$
9. $$2 \frac{6}{7}: \frac{5}{6} - \frac{9}{14} = \frac{20}{7} : \frac{5}{6} - \frac{9}{14} = \frac{20}{7} \cdot \frac{6}{5} - \frac{9}{14} = \frac{20 \cdot 6}{7 \cdot 5} - \frac{9}{14} = \frac{4 \cdot 5 \cdot 6}{7 \cdot 5} - \frac{9}{14} = \frac{24}{7} - \frac{9}{14} = \frac{24 \cdot 2}{7 \cdot 2} - \frac{9}{14} = \frac{48}{14} - \frac{9}{14} = \frac{39}{14} = 2 \frac{11}{14}$$

Ответ: 1) 8; 2) $$12 \frac{1}{2}$$; 3) $$\frac{39}{88}$$; 4) $$\frac{6}{11}$$; 5) $$2 \frac{1}{12}$$; 6) $$23 \frac{1}{13}$$; 7) $$\frac{3}{4}$$; 8) 15; 9) $$2 \frac{11}{14}$$