Решение:
\[ 5\frac{3}{10} + 2\frac{1}{5} = 5\frac{3}{10} + 2\frac{1 imes 2}{5 imes 2} = 5\frac{3}{10} + 2\frac{2}{10} = (5+2) + (\frac{3}{10} + \frac{2}{10}) = 7 + \frac{3+2}{10} = 7 + \frac{5}{10} = 7\frac{5}{10} \]
Ответ: $$7\frac{5}{10}$$