a)\(\dfrac{8}{5}+\dfrac{7}{6}+\dfrac{5}{9}-2\)
\(=\dfrac{144}{90}+\dfrac{105}{6}+\dfrac{50}{90}-\dfrac{180}{90}=\dfrac{119}{90}\)
b) \(3-\dfrac{5}{6}-\dfrac{4}{9}+\dfrac{32}{24}\)
\(=3-\dfrac{5}{6}-\dfrac{4}{9}+\dfrac{4}{3}\)
\(=\dfrac{54}{18}-\dfrac{15}{18}-\dfrac{8}{18}+\dfrac{24}{18}=\dfrac{55}{18}\)