Ответ: -3/8
\[24 \cdot \frac{3}{64} = \frac{24 \cdot 3}{64} = \frac{72}{64} = \frac{9}{8}\]
\[\frac{9}{8} - \frac{3}{4} = \frac{9}{8} - \frac{3 \cdot 2}{4 \cdot 2} = \frac{9}{8} - \frac{6}{8} = \frac{9 - 6}{8} = \frac{3}{8}\]
\[-\frac{3}{8}\]
Ответ: -3/8