Simplify: \(\dfrac{\tfrac{1}{4}+\tfrac{1}{5}}{1-\tfrac{3}{8}\times\tfrac{3}{5}}\)
\(\dfrac{18}{31}\)
Numerator: \(\dfrac{1}{4}+\dfrac{1}{5}=\dfrac{9}{20}\). Denominator: \(1-\dfrac{9}{40}=\dfrac{31}{40}\). So result = \(\dfrac{9}{20}\div\dfrac{31}{40}=\dfrac{9}{20}\times\dfrac{40}{31}=\dfrac{18}{31}\).