a) $$\frac{9}{16} : 6 = \frac{9}{16} \cdot \frac{1}{6} = \frac{9}{96}$$
12 : $$\frac{5}{8}$$ = 12 * $$\frac{8}{5}$$ = $$\frac{96}{5}$$
б) $$\frac{3}{10} : \frac{8}{11} = \frac{3}{10} \cdot \frac{11}{8} = \frac{33}{80}$$
$$\frac{7}{12} : 3\frac{1}{16} = \frac{7}{12} : \frac{49}{16} = \frac{7}{12} \cdot \frac{16}{49} = \frac{112}{588}$$
Ответ: a) $$\frac{9}{16} \cdot \frac{1}{6}$$, 12 * $$\frac{8}{5}$$; б) $$\frac{3}{10} \cdot \frac{11}{8}$$, $$\frac{7}{12} \cdot \frac{16}{49}$$