\[ 18 \frac{7}{10} - 15 \frac{3}{10} = (18 - 15) + \left(\frac{7}{10} - \frac{3}{10}\right) = 3 + \frac{4}{10} = 3 \frac{4}{10} = 3 \frac{2}{5} \]
Ответ: 3 2/5