3) 3 * 6/7 = ...

Давай решим эти примеры на действия с дробями. 3) $3 \cdot \frac{6}{7} = \frac{3 \cdot 6}{7} = \frac{18}{7} = 2\frac{4}{7}$ 4) $\frac{1}{9} \cdot \frac{4}{7} = \frac{1 \cdot 4}{9 \cdot 7} = \frac{4}{63}$ 5) $\frac{5}{6} \cdot \frac{1}{17} = \frac{5 \cdot 1}{6 \cdot 17} = \frac{5}{102}$ 6) $\frac{3}{4} \cdot \frac{13}{8} = \frac{3 \cdot 13}{4 \cdot 8} = \frac{39}{32} = 1\frac{7}{32}$ 7) $\frac{5}{7} \cdot \frac{25}{42} = \frac{5 \cdot 25}{7 \cdot 42} = \frac{125}{294}$ 8) $\frac{3}{13} \cdot \frac{1}{2} = \frac{3}{26}$ 9) $\frac{4}{5} + \frac{8}{25} = \frac{4 \cdot 5}{25} + \frac{8}{25} = \frac{20 + 8}{25} = \frac{28}{25} = 1\frac{3}{25}$ 10) $\frac{2}{7} \div \frac{2}{5} = \frac{2}{7} \cdot \frac{5}{2} = \frac{5}{7}$ 11) $\frac{3}{11} \cdot \frac{1}{3} = \frac{1}{11}$ 12) $\frac{3}{14} \cdot 2 = \frac{6}{14} = \frac{3}{7}$ 13) $\frac{1}{5} \div 3 = \frac{1}{5} \cdot \frac{1}{3} = \frac{1}{15}$ 14) $\frac{2}{17} \cdot 8 = \frac{16}{17}$ 15) $\frac{3}{26} \cdot 3 = \frac{9}{26}$ 16) $\frac{25}{55} \cdot \frac{11}{24} = \frac{5}{11} \cdot \frac{11}{24} = \frac{5}{24}$ 17) $\frac{27}{25} \cdot \frac{10}{2} = \frac{27 \cdot 10}{25 \cdot 2} = \frac{270}{50} = \frac{27}{5} = 5\frac{2}{5}$ 18) $\frac{2}{9} \div \frac{2}{9} = 1$ 19) $\frac{3}{9} \div \frac{3}{4} = \frac{1}{3} \cdot \frac{4}{3} = \frac{4}{9}$ 20) $\frac{1}{24} \div \frac{10}{20} = \frac{1}{24} \cdot 2 = \frac{2}{24} = \frac{1}{12}$