Решение:

a) $$6+\frac{8}{13} = \frac{6 \cdot 13}{13} + \frac{8}{13} = \frac{78}{13} + \frac{8}{13} = \frac{78+8}{13} = \frac{86}{13} = 6\frac{8}{13}$$

б) $$12+\frac{19}{24} = \frac{12 \cdot 24}{24} + \frac{19}{24} = \frac{288}{24} + \frac{19}{24} = \frac{288+19}{24} = \frac{307}{24} = 12\frac{19}{24}$$

в) $$5\frac{7}{15}+8\frac{4}{15} = (5+8) + (\frac{7}{15} + \frac{4}{15}) = 13 + \frac{7+4}{15} = 13 + \frac{11}{15} = 13\frac{11}{15}$$

г) $$13\frac{5}{101}+7\frac{25}{101} = (13+7) + (\frac{5}{101} + \frac{25}{101}) = 20 + \frac{5+25}{101} = 20 + \frac{30}{101} = 20\frac{30}{101}$$

Ответ:

• a) $$6\frac{8}{13}$$
• б) $$12\frac{19}{24}$$
• в) $$13\frac{11}{15}$$
• г) $$20\frac{30}{101}$$