Выполни действия с дробями: a) 5/4 : 2/15

a) $\frac{5}{4} : \frac{2}{15} = \frac{5}{4} \cdot \frac{15}{2} = \frac{5 \cdot 15}{4 \cdot 2} = \frac{75}{8} = 9\frac{3}{8}$ б) $\frac{2}{3} : \frac{8}{9} = \frac{2}{3} \cdot \frac{9}{8} = \frac{2 \cdot 9}{3 \cdot 8} = \frac{18}{24} = \frac{3}{4}$ в) $\frac{64}{131} : \frac{32}{52} = \frac{64}{131} \cdot \frac{52}{32} = \frac{64 \cdot 52}{131 \cdot 32} = \frac{2 \cdot 52}{131} = \frac{104}{131}$ г) $\frac{64}{125} : 4 = \frac{64}{125} \cdot \frac{1}{4} = \frac{64}{125 \cdot 4} = \frac{16}{125}$ д) $9 : \frac{3}{4} = 9 \cdot \frac{4}{3} = \frac{9 \cdot 4}{3} = \frac{36}{3} = 12$ е) $9 : 4 = \frac{9}{4} = 2\frac{1}{4}$ ж) $1\frac{3}{7} : 1\frac{1}{14} = \frac{10}{7} : \frac{15}{14} = \frac{10}{7} \cdot \frac{14}{15} = \frac{10 \cdot 14}{7 \cdot 15} = \frac{2 \cdot 2}{1 \cdot 3} = \frac{4}{3} = 1\frac{1}{3}$ и) $3\frac{8}{19} : 5\frac{15}{38} = \frac{65}{19} : \frac{205}{38} = \frac{65}{19} \cdot \frac{38}{205} = \frac{65 \cdot 38}{19 \cdot 205} = \frac{1 \cdot 2}{1 \cdot 1} = \frac{2}{1} = 2$ з) $2\frac{1}{3} : 7\frac{1}{9} = \frac{7}{3} : \frac{64}{9} = \frac{7}{3} \cdot \frac{9}{64} = \frac{7 \cdot 9}{3 \cdot 64} = \frac{7 \cdot 3}{1 \cdot 64} = \frac{21}{64}$ к) $4\frac{17}{36} : 19\frac{1}{6} = \frac{161}{36} : \frac{115}{6} = \frac{161}{36} \cdot \frac{6}{115} = \frac{161 \cdot 6}{36 \cdot 115} = \frac{161}{6 \cdot 115} = \frac{161}{690}$