Найдите частное: a) $\frac{5}{4} : \frac{2}{15}$; б) $\frac{2}{3} : \frac{8}{9}$; в) $\frac{64}{131} : \frac{32}{52}$; г) $\frac{64}{125} : \frac{4}{1}$; д) $9 : \frac{3}{4}$

a) $\frac{5}{4} : \frac{2}{15} = \frac{5}{4} \cdot \frac{15}{2} = \frac{75}{8} = 9\frac{3}{8}$; б) $\frac{2}{3} : \frac{8}{9} = \frac{2}{3} \cdot \frac{9}{8} = \frac{18}{24} = \frac{3}{4}$; в) $\frac{64}{131} : \frac{32}{52} = \frac{64}{131} \cdot \frac{52}{32} = \frac{2}{131} \cdot 52 = \frac{104}{131}$; г) $\frac{64}{125} : 4 = \frac{64}{125} \cdot \frac{1}{4} = \frac{16}{125}$; д) $9 : \frac{3}{4} = 9 \cdot \frac{4}{3} = \frac{36}{3} = 12$.