\[\frac{7}{8} + \frac{3}{4} = \frac{7}{8} + \frac{3 \cdot 2}{4 \cdot 2} = \frac{7}{8} + \frac{6}{8} = \frac{7+6}{8} = \frac{13}{8}\]
\[9 \cdot \frac{13}{8} = \frac{9 \cdot 13}{8} = \frac{117}{8}\]
\[1 : \frac{5}{6} \cdot \frac{25}{48} = \frac{6}{5} \cdot \frac{25}{48} = \frac{6 \cdot 25}{5 \cdot 48} = \frac{150}{240} = \frac{5}{8}\]
\[\frac{117}{8} - \frac{5}{8} = \frac{117 - 5}{8} = \frac{112}{8} = 14\]
Ответ: 14