Ответ:

\(5\frac{5}{6}+8\frac{2}{9}=\frac{35}{6}+\frac{74}{9}=\frac{253}{18}\).

\(\frac{253}{18}:25.3=\frac{253}{18}:\frac{253}{10}=\frac{5}{9}\).

\(1.5:\frac{27}{28}=\frac{3}{2}\cdot\frac{28}{27}=\frac{14}{9}\).

\(\frac{5}{9}-3\frac{1}{9}+\frac{14}{9}=\frac{5}{9}-\frac{28}{9}+\frac{14}{9}=-1\).

Ответ: −1.