\(\dfrac{14}{8}:\dfrac{7}{12}-\dfrac{3}{8}:\dfrac{9}{5}\\ =\dfrac{7}{4}:\dfrac{7}{12}-\dfrac{3}{8}:\dfrac{9}{5}\\ =\dfrac{7}{4}\times\dfrac{12}{7}-\dfrac{3}{8}\times\dfrac{5}{9}\\ =\dfrac{12}{4}-\dfrac{1\times5}{8\times3}\\ =3-\dfrac{5}{24}\\ =\dfrac{3\times24-5}{24}\\ =\dfrac{72-5}{24}\\ =\dfrac{67}{24}\)