3. \(\frac{7}{6}-\frac{9}{5}\)

Общий знаменатель дробей — 30:

\(\frac{7}{6}=\frac{35}{30}\), \(\frac{9}{5}=\frac{54}{30}\).

\(\frac{35}{30}-\frac{54}{30}=-\frac{19}{30}\).

Ответ: \(-\frac{19}{30}\).