e:
г) $$\frac{64}{125} : 4 = \frac{64}{125} : \frac{4}{1} = \frac{64}{125} \cdot \frac{1}{4} = \frac{16}{125}$$
Ответ: $$\frac{16}{125}$$
д) $$9 : \frac{3}{4} = \frac{9}{1} : \frac{3}{4} = \frac{9}{1} \cdot \frac{4}{3} = \frac{3 \cdot 4}{1} = 12$$
Ответ: 12
e) $$9 : 4 = \frac{9}{4} = 2\frac{1}{4}$$
Ответ: $$2\frac{1}{4}$$
-)
$$\frac{2}{3} \cdot \frac{8}{9} = \frac{2 \cdot 8}{3 \cdot 9} = \frac{16}{27}$$
Ответ: $$\frac{16}{27}$$
B)
$$\frac{64}{131} : \frac{32}{52} = \frac{64}{131} \cdot \frac{52}{32} = \frac{2}{131} \cdot \frac{52}{1} = \frac{104}{131}$$
Ответ: $$\frac{104}{131}$$