Выполни действие:

1) $\frac{18}{19} : 9 = \frac{18}{19 \cdot 9} = \frac{2}{19}$ 2) $3\frac{3}{13} \cdot \frac{3}{70} = \frac{42}{13} \cdot \frac{3}{70} = \frac{6 \cdot 3}{13 \cdot 10} = \frac{18}{130} = \frac{9}{65}$ 3) $\frac{7}{18} : \frac{21}{40} = \frac{7}{18} \cdot \frac{40}{21} = \frac{1 \cdot 20}{9 \cdot 3} = \frac{20}{27}$ 4) $\frac{6}{19} \cdot 10 = \frac{60}{19} = 3\frac{3}{19}$ 5) $3\frac{4}{9} : \frac{17}{18} = \frac{31}{9} \cdot \frac{18}{17} = \frac{31 \cdot 2}{17} = \frac{62}{17} = 3\frac{11}{17}$ 6) $25 : \frac{10}{11} = 25 \cdot \frac{11}{10} = \frac{5 \cdot 11}{2} = \frac{55}{2} = 27\frac{1}{2}$ 7) $\frac{11}{24} \cdot 2\frac{11}{32} = \frac{11}{24} \cdot \frac{75}{32} = \frac{11 \cdot 25}{8 \cdot 32} = \frac{275}{256} = 1\frac{19}{256}$ 8) $2\frac{2}{5} : 2\frac{4}{7} = \frac{12}{5} : \frac{18}{7} = \frac{12}{5} \cdot \frac{7}{18} = \frac{2 \cdot 7}{5 \cdot 3} = \frac{14}{15}$ 9) $63 \cdot 1\frac{2}{9} = 63 \cdot \frac{11}{9} = 7 \cdot 11 = 77$ 10) $4 : \frac{11}{13} = 4 \cdot \frac{13}{11} = \frac{52}{11} = 4\frac{8}{11}$ 11) $\frac{7}{125} \cdot \frac{3}{4} = \frac{21}{500}$ 12) $4\frac{2}{3} \cdot 2\frac{1}{5} = \frac{14}{3} \cdot \frac{11}{5} = \frac{154}{15} = 10\frac{4}{15}$