5.541 Вычислите: a) 5:\frac{2}{3}; б) \frac{3}{8}:\frac{1}{3}; в) \frac{1}{12}:\frac{5}{36}; г) \frac{14}{55} \cdot \frac{5}{21}; д) \frac{121}{234} \cdot \frac{11}{12}

а) 5:\frac{2}{3} = \frac{5}{1}:\frac{2}{3} = \frac{5}{1} \cdot \frac{3}{2} = \frac{5\cdot3}{1\cdot2} = \frac{15}{2} = 7.5

б) \frac{3}{8}:\frac{1}{3} = \frac{3}{8} \cdot \frac{3}{1} = \frac{3\cdot3}{8\cdot1} = \frac{9}{8} = 1\frac{1}{8}

в) \frac{1}{12}:\frac{5}{36} = \frac{1}{12} \cdot \frac{36}{5} = \frac{1\cdot36}{12\cdot5} = \frac{36}{60} = \frac{3}{5}

г) \frac{14}{55} \cdot \frac{5}{21} = \frac{14\cdot5}{55\cdot21} = \frac{2\cdot1}{11\cdot3} = \frac{2}{33}

д) \frac{121}{234} \cdot \frac{11}{12} = \frac{121\cdot11}{234\cdot12} = \frac{1331}{2808}