а) $$8 + \frac{3}{5} = 8 \frac{3}{5} = \frac{8 \cdot 5 + 3}{5} = \frac{40 + 3}{5} = \frac{43}{5}$$
б) $$30 + \frac{10}{20} = 30 \frac{10}{20} = \frac{30 \cdot 20 + 10}{20} = \frac{600 + 10}{20} = \frac{610}{20} = \frac{61}{2}$$
в) $$54 + \frac{34}{46} = 54 \frac{34}{46} = \frac{54 \cdot 46 + 34}{46} = \frac{2484 + 34}{46} = \frac{2518}{46} = \frac{1259}{23}$$
Ответ:
a) $$8 \frac{3}{5} = \frac{43}{5}$$
б) $$30 \frac{10}{20} = \frac{61}{2}$$
в) $$54 \frac{34}{46} = \frac{1259}{23}$$