Решим по порядку представленные примеры:
1) $$8\frac{1}{25}-7\frac{4}{5} = \frac{201}{25} - \frac{39}{5} = \frac{201}{25} - \frac{195}{25} = \frac{6}{25}$$
2) $$4\frac{2}{81}-3\frac{2}{27} = \frac{326}{81} - \frac{83}{27} = \frac{326}{81} - \frac{249}{81} = \frac{77}{81}$$
3) $$7\frac{2}{15}+4\frac{3}{16} = \frac{107}{15} + \frac{67}{16} = \frac{1712}{240} + \frac{1005}{240} = \frac{2717}{240} = 11\frac{77}{240}$$
6) $$8-\frac{5}{13} = \frac{8 \cdot 13}{13} - \frac{5}{13} = \frac{104}{13} - \frac{5}{13} = \frac{99}{13} = 7\frac{8}{13}$$
7) $$16\frac{3}{5}+17\frac{7}{10} = \frac{83}{5} + \frac{177}{10} = \frac{166}{10} + \frac{177}{10} = \frac{343}{10} = 34\frac{3}{10}$$
8) $$6\frac{1}{36}-5\frac{3}{16} = \frac{217}{36} - \frac{83}{16} = \frac{868}{144} - \frac{747}{144} = \frac{121}{144}$$
Решим уравнение:
а) $$a = 7\frac{5}{8} + \frac{7}{12} = \frac{61}{8} + \frac{7}{12} = \frac{183}{24} + \frac{14}{24} = \frac{197}{24} = 8\frac{5}{24}$$