Ответ: a) 15/77; б) 1/15; в) 32/3; г) 22; д) 3/2; e) 2/13
a) \[\frac{3}{7} \cdot \frac{5}{11} = \frac{3 \cdot 5}{7 \cdot 11} = \frac{15}{77}\]
б) \[\frac{6}{25} \cdot \frac{5}{18} = \frac{6 \cdot 5}{25 \cdot 18} = \frac{30}{450} = \frac{1}{15}\]
в) \[3\frac{3}{5} \cdot 1\frac{1}{9} = \frac{3 \cdot 5 + 3}{5} \cdot \frac{1 \cdot 9 + 1}{9} = \frac{18}{5} \cdot \frac{10}{9} = \frac{18 \cdot 10}{5 \cdot 9} = \frac{180}{45} = \frac{36}{9} = 4\]
г) \[1\frac{3}{7} \cdot 14 = \frac{1 \cdot 7 + 3}{7} \cdot 14 = \frac{10}{7} \cdot 14 = \frac{10 \cdot 14}{7} = \frac{140}{7} = 20\]
д) \[\frac{5}{9} : \frac{10}{27} = \frac{5}{9} \cdot \frac{27}{10} = \frac{5 \cdot 27}{9 \cdot 10} = \frac{135}{90} = \frac{27}{18} = \frac{3}{2}\]
e) \[\frac{12}{13} : 6 = \frac{12}{13} \cdot \frac{1}{6} = \frac{12 \cdot 1}{13 \cdot 6} = \frac{12}{78} = \frac{2}{13}\]
Ответ: a) 15/77; б) 1/15; в) 32/3; г) 22; д) 3/2; e) 2/13