\[\frac{9}{4}+\frac{5}{6}-\frac{7}{8}+\frac{10}{6} = \frac{9 \cdot 6}{4\cdot 6}+\frac{5\cdot 4}{6\cdot 4}-\frac{7\cdot 3}{8\cdot 3}+\frac{10\cdot 4}{6\cdot 4} = \\
= \frac{54+20-21+40}{24} = \frac{74+19}{24} = \frac{93}{24} = 3.875\]

Ҷавоб:   \( 3.875; \)