Решение:
- \( 1 \frac{2}{8} = \frac{10}{8} = \frac{5}{4} \)
- \( \frac{5}{4} - \frac{5}{2} = \frac{5}{4} - \frac{10}{4} = -\frac{5}{4} \)
- \( 3 \frac{1}{3} = \frac{10}{3} \)
- \( \frac{10}{3} \cdot \left(-\frac{5}{4}\right) = -\frac{50}{12} = -\frac{25}{6} \)
- \( 8 \frac{1}{7} = \frac{57}{7} \)
- \( 1 \frac{3}{7} = \frac{10}{7} \)
- \( \frac{57}{7} : \frac{10}{7} = \frac{57}{7} \cdot \frac{7}{10} = \frac{57}{10} \)
- \( -\frac{25}{6} + \frac{57}{10} = -\frac{125}{30} + \frac{171}{30} = \frac{46}{30} = \frac{23}{15} \)
Ответ: \(\frac{23}{15}\).