2. Выполните действия и сократите результат: a) $$3\frac{11}{15}+2\frac{7}{15}$$; б) $$5\frac{7}{16}-3\frac{13}{16}$$.

a) $$3\frac{11}{15}+2\frac{7}{15} = (3+2) + (\frac{11}{15}+\frac{7}{15}) = 5 + \frac{18}{15} = 5 + \frac{6}{5} = 5 + 1\frac{1}{5} = 6\frac{1}{5}$$

б) $$5\frac{7}{16}-3\frac{13}{16} = 5\frac{7}{16}-3\frac{13}{16} = (4+\frac{16}{16} + \frac{7}{16}) - 3\frac{13}{16} = 4\frac{23}{16} - 3\frac{13}{16} = (4-3) + (\frac{23}{16}-\frac{13}{16}) = 1 + \frac{10}{16} = 1 + \frac{5}{8} = 1\frac{5}{8}$$