4 +2= 5

3/5 + 2 4/5 = 3 2/5

$$\frac{3}{5} + 2 \frac{4}{5} = 2 + \frac{3}{5} + \frac{4}{5} = 2 + \frac{3+4}{5} = 2 + \frac{7}{5} = 2 + 1 \frac{2}{5} = 3 \frac{2}{5}$$

Ответ: $$3 \frac{2}{5}$$