a) $$7 + 2\frac{5}{8}$$
$$7 + 2\frac{5}{8} = 7 + 2 + \frac{5}{8} = 9 + \frac{5}{8} = 9\frac{5}{8}$$
Ответ: $$9\frac{5}{8}$$
б) $$9\frac{1}{9} + 20$$
$$9\frac{1}{9} + 20 = 9 + \frac{1}{9} + 20 = 29 + \frac{1}{9} = 29\frac{1}{9}$$
Ответ: $$29\frac{1}{9}$$