b: \(=\dfrac{1}{9}\cdot\dfrac{3}{5}+\dfrac{5}{6}\cdot\dfrac{3}{5}-\dfrac{7}{2}\cdot\dfrac{3}{5}\)
\(=\dfrac{3}{5}\left(\dfrac{1}{9}+\dfrac{5}{6}-\dfrac{7}{2}\right)=\dfrac{3}{5}\cdot\dfrac{-23}{9}=\dfrac{-69}{45}=\dfrac{-23}{15}\)
d: \(=\left(\dfrac{5}{13}+\dfrac{8}{13}\right)+\left(-\dfrac{20}{41}-\dfrac{21}{41}\right)-\dfrac{5}{7}=-\dfrac{5}{7}\)