220. Выполните вычитание: a) $$8\frac{9}{11} - 3\frac{5}{11}$$; б) $$6\frac{5}{8} - 4$$; в) $$9 - \frac{5}{6}$$; г) $$9 - 3\frac{5}{8}$$; д) $$8\frac{2}{7} - 3\frac{5}{7}$$; е) $$8\frac{3}{8} - 5\frac{3}{8}$$

a) $$8\frac{9}{11} - 3\frac{5}{11} = (8-3) + (\frac{9}{11} - \frac{5}{11}) = 5 + \frac{9-5}{11} = 5 + \frac{4}{11} = 5\frac{4}{11}$$ б) $$6\frac{5}{8} - 4 = (6-4) + \frac{5}{8} = 2 + \frac{5}{8} = 2\frac{5}{8}$$ в) $$9 - \frac{5}{6} = 8\frac{6}{6} - \frac{5}{6} = 8\frac{6-5}{6} = 8\frac{1}{6}$$ г) $$9 - 3\frac{5}{8} = 8\frac{8}{8} - 3\frac{5}{8} = (8-3) + (\frac{8}{8} - \frac{5}{8}) = 5 + \frac{8-5}{8} = 5 + \frac{3}{8} = 5\frac{3}{8}$$ д) $$8\frac{2}{7} - 3\frac{5}{7} = (8-3) + (\frac{2}{7} - \frac{5}{7}) = 5 + (\frac{2-5}{7}) = 5 - \frac{3}{7} = 4\frac{7}{7} - \frac{3}{7} = 4\frac{4}{7}$$ е) $$8\frac{3}{8} - 5\frac{3}{8} = (8-5) + (\frac{3}{8} - \frac{3}{8}) = 3 + 0 = 3$$