Решение:

Чтобы разделить одну дробь на другую, нужно первую дробь умножить на дробь, обратную второй.

1. $$\frac{4}{5} : \frac{9}{11} = \frac{4}{5} * \frac{11}{9} = \frac{4 * 11}{5 * 9} = \frac{44}{45}$$
2. $$\frac{1}{7} : \frac{5}{8} = \frac{1}{7} * \frac{8}{5} = \frac{1 * 8}{7 * 5} = \frac{8}{35}$$
3. $$\frac{2}{7} : \frac{2}{9} = \frac{2}{7} * \frac{9}{2} = \frac{2 * 9}{7 * 2} = \frac{18}{14} = \frac{9}{7} = 1\frac{2}{7}$$
4. $$\frac{5}{8} : \frac{7}{12} = \frac{5}{8} * \frac{12}{7} = \frac{5 * 12}{8 * 7} = \frac{60}{56} = \frac{15}{14} = 1\frac{1}{14}$$
5. $$\frac{4}{7} : \frac{16}{49} = \frac{4}{7} * \frac{49}{16} = \frac{4 * 49}{7 * 16} = \frac{196}{112} = \frac{7}{4} = 1\frac{3}{4}$$
6. $$\frac{5}{9} : \frac{1}{2} = \frac{5}{9} * \frac{2}{1} = \frac{5 * 2}{9 * 1} = \frac{10}{9} = 1\frac{1}{9}$$
7. $$\frac{12}{25} : \frac{8}{15} = \frac{12}{25} * \frac{15}{8} = \frac{12 * 15}{25 * 8} = \frac{180}{200} = \frac{9}{10}$$
8. $$\frac{9}{14} : \frac{18}{35} = \frac{9}{14} * \frac{35}{18} = \frac{9 * 35}{14 * 18} = \frac{315}{252} = \frac{5}{4} = 1\frac{1}{4}$$