5.277 Найдите сумму: a) 7+2\frac{5}{8}; 6) 9\frac{1}{9} + 20;

a) $$7 + 2\frac{5}{8} = 7 + \frac{2 \cdot 8 + 5}{8} = 7 + \frac{16 + 5}{8} = 7 + \frac{21}{8} = 7 + 2\frac{5}{8} = 9\frac{5}{8}$$

б) $$9\frac{1}{9} + 20 = \frac{9 \cdot 9 + 1}{9} + 20 = \frac{81 + 1}{9} + 20 = \frac{82}{9} + 20 = 9\frac{1}{9} + 20 = 29\frac{1}{9}$$

Ответ: a) $$9\frac{5}{8}$$; б) $$29\frac{1}{9}$$