(7 - 8 4/5) * 2 7/9 - 15 : (1/8 - 3/4)

Решение:

1. \( 7 - 8\frac{4}{5} = \frac{35}{5} - \frac{44}{5} = -\frac{9}{5} \)
2. \( 2\frac{7}{9} = \frac{18}{9} + \frac{7}{9} = \frac{25}{9} \)
3. \( \frac{1}{8} - \frac{3}{4} = \frac{1}{8} - \frac{6}{8} = -\frac{5}{8} \)
4. \( -\frac{9}{5} \cdot \frac{25}{9} = -\frac{9 \cdot 25}{5 \cdot 9} = -5 \)
5. \( 15 : \left(-\frac{5}{8}\right) = 15 \cdot \left(-\frac{8}{5}\right) = -\frac{15 \cdot 8}{5} = -24 \)
6. \( -5 - (-24) = -5 + 24 = 19 \)

Ответ: 19