а) $$2 + \frac{4}{7} = 2\frac{4}{7} = \frac{2 \cdot 7 + 4}{7} = \frac{18}{7}$$
б) $$10 + \frac{20}{30} = 10\frac{20}{30} = 10\frac{2}{3} = \frac{10 \cdot 3 + 2}{3} = \frac{32}{3}$$
в) $$34 + \frac{46}{67} = 34\frac{46}{67} = \frac{34 \cdot 67 + 46}{67} = \frac{2324}{67}$$
Ответ: а) 2\frac{4}{7} = \frac{18}{7}; б) 10\frac{2}{3} = \frac{32}{3}; в) 34\frac{46}{67} = \frac{2324}{67}