3. Выполните действия: a) \(\frac{3}{7}:\frac{7}{9}\) б) \(\frac{5}{28}:\frac{15}{42}\) v) \(\frac{6}{13}:\frac{9}{52}\) г) \(56:\frac{7}{8}\) д) \(2\frac{3}{5}:\frac{13}{20}\) e) \(3\frac{3}{4}:4\frac{3}{8}\)

a) \(\frac{3}{7} : \frac{7}{9} = \frac{3}{7} \cdot \frac{9}{7} = \frac{3 \cdot 9}{7 \cdot 7} = \frac{27}{49}\) б) \(\frac{5}{28} : \frac{15}{42} = \frac{5}{28} \cdot \frac{42}{15} = \frac{5 \cdot 42}{28 \cdot 15} = \frac{1 \cdot 3}{2 \cdot 1} = \frac{3}{2} = 1\frac{1}{2}\) в) \(\frac{6}{13} : \frac{9}{52} = \frac{6}{13} \cdot \frac{52}{9} = \frac{6 \cdot 52}{13 \cdot 9} = \frac{2 \cdot 4}{1 \cdot 3} = \frac{8}{3} = 2\frac{2}{3}\) г) \(56 : \frac{7}{8} = 56 \cdot \frac{8}{7} = \frac{56 \cdot 8}{7} = \frac{8 \cdot 8}{1} = 64\) д) \(2\frac{3}{5} : \frac{13}{20} = \frac{13}{5} \cdot \frac{20}{13} = \frac{13 \cdot 20}{5 \cdot 13} = \frac{1 \cdot 4}{1 \cdot 1} = 4\) e) \(3\frac{3}{4} : 4\frac{3}{8} = \frac{15}{4} : \frac{35}{8} = \frac{15}{4} \cdot \frac{8}{35} = \frac{15 \cdot 8}{4 \cdot 35} = \frac{3 \cdot 2}{1 \cdot 7} = \frac{6}{7}\) \textbf{Ответ:} a) \(\frac{27}{49}\); б) \(1\frac{1}{2}\); в) \(2\frac{2}{3}\); г) 64; д) 4; e) \(\frac{6}{7}\)