a) $$\frac{5}{4} : \frac{2}{15} = \frac{5}{4} \cdot \frac{15}{2} = \frac{5 \cdot 15}{4 \cdot 2} = \frac{75}{8} = 9\frac{3}{8}$$
Ответ: $$9\frac{3}{8}$$
б) $$\frac{2}{3} : \frac{8}{9} = \frac{2}{3} \cdot \frac{9}{8} = \frac{2 \cdot 9}{3 \cdot 8} = \frac{2 \cdot 3 \cdot 3}{3 \cdot 2 \cdot 4} = \frac{3}{4}$$
Ответ: $$\frac{3}{4}$$
в) $$\frac{64}{131} : \frac{32}{52} = \frac{64}{131} \cdot \frac{52}{32} = \frac{32 \cdot 2 \cdot 52}{131 \cdot 32} = \frac{2 \cdot 52}{131} = \frac{2 \cdot 4 \cdot 13}{131} = \frac{8 \cdot 13}{131} = \frac{104}{131}$$
Ответ: $$\frac{104}{131}$$
г) $$\frac{64}{125} : 4 = \frac{64}{125} : \frac{4}{1} = \frac{64}{125} \cdot \frac{1}{4} = \frac{16 \cdot 4 \cdot 1}{125 \cdot 4} = \frac{16}{125}$$
Ответ: $$\frac{16}{125}$$
д) $$9 : \frac{3}{4} = \frac{9}{1} : \frac{3}{4} = \frac{9}{1} \cdot \frac{4}{3} = \frac{9 \cdot 4}{1 \cdot 3} = \frac{3 \cdot 3 \cdot 4}{1 \cdot 3} = 3 \cdot 4 = 12$$
Ответ: 12
e) $$9 : 4 = \frac{9}{1} : \frac{4}{1} = \frac{9}{4} = 2\frac{1}{4}$$
Ответ: $$2\frac{1}{4}$$