a: \(=\dfrac{1}{3}-\dfrac{6}{13}\cdot\dfrac{13}{36}\cdot\dfrac{9}{10}\)
\(=\dfrac{1}{3}-\dfrac{1}{6}\cdot\dfrac{9}{10}\)
\(=\dfrac{1}{3}-\dfrac{3}{20}=\dfrac{20-9}{60}=\dfrac{11}{60}\)
b: \(=\dfrac{1}{3}\cdot\dfrac{15}{7}\cdot\dfrac{34}{45}=\dfrac{15}{45}\cdot\dfrac{1}{3}\cdot\dfrac{34}{7}=\dfrac{34}{63}\)