7. \(2\frac{3}{10}+5\frac{1}{15}-1\frac{1}{6}\) (цепочка)

Приведём дроби к общему знаменателю 30:

\(\frac{3}{10}=\frac{9}{30}\), \(\frac{1}{15}=\frac{2}{30}\), \(\frac{1}{6}=\frac{5}{30}\).

\(2\frac{3}{10}+5\frac{1}{15}-1\frac{1}{6}=6+\frac{9}{30}+\frac{2}{30}-\frac{5}{30}\).

\(6+\frac{6}{30}=6+\frac{1}{5}=6\frac{1}{5}\).

Ответ: \(6\frac{1}{5}\).