17. Выполните действие: a) $$6\frac{5}{6} + 4\frac{1}{4}$$; в) $$10\frac{3}{10} - 15\frac{4}{15}$$; г) $$5 - 3\frac{2}{7}$$; д) $$9\frac{4}{8} \cdot \frac{3}{8}$$; e) $$\frac{5}{8} : \frac{9}{10}$$; ж) $$2\frac{6}{7} : 1\frac{3}{7}$$; з) $$6\frac{3}{5} \cdot 10$$.

a) $$6\frac{5}{6} + 4\frac{1}{4} = \frac{41}{6} + \frac{17}{4} = \frac{82}{12} + \frac{51}{12} = \frac{133}{12} = 11\frac{1}{12}$$

в) $$10\frac{3}{10} - 15\frac{4}{15} = \frac{103}{10} - \frac{229}{15} = \frac{309}{30} - \frac{458}{30} = -\frac{149}{30} = -4\frac{29}{30}$$

г) $$5 - 3\frac{2}{7} = \frac{5}{1} - \frac{23}{7} = \frac{35}{7} - \frac{23}{7} = \frac{12}{7} = 1\frac{5}{7}$$

д) $$9\frac{4}{8} \cdot \frac{3}{8} = \frac{76}{8} \cdot \frac{3}{8} = \frac{228}{64} = \frac{57}{16} = 3\frac{9}{16}$$

e) $$\frac{5}{8} : \frac{9}{10} = \frac{5}{8} \cdot \frac{10}{9} = \frac{50}{72} = \frac{25}{36}$$

ж) $$2\frac{6}{7} : 1\frac{3}{7} = \frac{20}{7} : \frac{10}{7} = \frac{20}{7} \cdot \frac{7}{10} = \frac{140}{70} = 2$$

з) $$6\frac{3}{5} \cdot 10 = \frac{33}{5} \cdot 10 = \frac{330}{5} = 66$$