a) $$1 - \frac{5}{6} = \frac{6}{6} - \frac{5}{6} = \frac{1}{6}$$
б) $$5 - 2\frac{9}{9} = 5 - 3 = 2$$
е) $$5 - \frac{5}{6} = 4\frac{6}{6} - \frac{5}{6} = 4\frac{1}{6}$$
г) $$8\frac{3}{6} - 7\frac{4}{6} = 7\frac{9}{6} - 7\frac{4}{6} = \frac{5}{6}$$
Ответ: a) $$\frac{1}{6}$$; б) $$2$$; е) $$4\frac{1}{6}$$; г) $$\frac{5}{6}$$