Найдите значение выражения: а) $$ 3\frac{11}{30} - 15\frac{4}{15} + 20\frac{1}{20} $$; б) $$ 9\frac{7}{9} - 5\frac{5}{11} $$; в) $$ 5\frac{4}{9} + 2\frac{5}{12} $$; г) $$ 7\frac{7}{16} + 2\frac{15}{24} $$; д) $$ 8\frac{1}{8} - 4\frac{7}{10} $$.

a) $$ 3\frac{11}{30} - 15\frac{4}{15} + 20\frac{1}{20} = 3\frac{11}{30} - 15\frac{8}{30} + 20\frac{3}{60} = 3\frac{22}{60} - 15\frac{16}{30} + 20\frac{3}{60} = -12 + \frac{11-16+3}{30} = 8\frac{25}{60} = -12\frac{1}{10} + 20\frac{3}{60} = 7\frac{5}{60} = 7\frac{1}{12} $$

б) $$ 9\frac{7}{9} - 5\frac{5}{11} = 9 + \frac{7}{9} - 5 - \frac{5}{11} = 4 + \frac{77}{99} - \frac{45}{99} = 4 + \frac{32}{99} = 4\frac{32}{99} $$

в) $$ 5\frac{4}{9} + 2\frac{5}{12} = 5\frac{16}{36} + 2\frac{15}{36} = 7 + \frac{31}{36} = 7\frac{31}{36} $$

г) $$ 7\frac{7}{16} + 2\frac{15}{24} = 7\frac{21}{48} + 2\frac{30}{48} = 9 + \frac{51}{48} = 9 + 1\frac{3}{48} = 10\frac{1}{16} $$

д) $$ 8\frac{1}{8} - 4\frac{7}{10} = 8\frac{5}{40} - 4\frac{28}{40} = 7\frac{45}{40} - 4\frac{28}{40} = 3\frac{17}{40} $$

Ответ:

1. $$ 8\frac{5}{12} $$
2. $$ 4\frac{32}{99} $$
3. $$ 7\frac{31}{36} $$
4. $$ 10\frac{1}{16} $$
5. $$ 3\frac{17}{40} $$