\(=\dfrac{17}{8}:\dfrac{51}{40}-\left(15-13-\dfrac{1}{3}\right):\dfrac{25}{6}\)
\(=\dfrac{5}{3}-\dfrac{5}{3}\cdot\dfrac{6}{25}=\dfrac{5}{3}\cdot\dfrac{19}{25}=\dfrac{19}{15}\)
\(2\dfrac{1}{8}:1\dfrac{11}{40}-\left(15-13\dfrac{1}{3}\right):4\dfrac{1}{6}\)
\(=\dfrac{17}{8}.\dfrac{40}{51}-\left(15-\dfrac{40}{3}\right).\dfrac{6}{25}\)
\(=\dfrac{17}{8}.\dfrac{40}{51}-\dfrac{5}{3}.\dfrac{6}{25}\)
\(=\dfrac{5}{3}-\dfrac{2}{5}\)
\(=\dfrac{19}{15}\)