a: \(=\dfrac{1}{5}\left(\dfrac{11}{16}+\dfrac{5}{16}\right)+\dfrac{4}{5}=\dfrac{1}{5}+\dfrac{4}{5}=1\)
b: \(=\dfrac{5}{9}\left(\dfrac{10}{11}+\dfrac{14}{11}-\dfrac{15}{11}\right)=\dfrac{5}{9}\cdot\dfrac{9}{11}=\dfrac{5}{11}\)
c: \(=\dfrac{1}{2}\cdot\dfrac{7}{3}+\dfrac{1}{3}\cdot\dfrac{4}{2}\)
\(=\dfrac{1}{3}\left(\dfrac{7}{2}+\dfrac{4}{2}\right)=\dfrac{1}{3}\cdot\dfrac{11}{2}=\dfrac{11}{6}\)
a: \(=\dfrac{-3}{5}\left(\dfrac{5}{7}+\dfrac{4}{7}\right)+\dfrac{3}{5}=\dfrac{-3}{5}\cdot\dfrac{9}{7}+\dfrac{3}{5}=\dfrac{-27}{35}+\dfrac{21}{35}=\dfrac{-6}{35}\)
b: \(=\dfrac{-4}{9}\left(\dfrac{3}{11}+\dfrac{8}{11}\right)-\dfrac{5}{9}=\dfrac{-4}{9}-\dfrac{5}{9}=-1\)
