\(D=\left(\dfrac{157}{8}:\dfrac{7}{12}-\dfrac{53}{4}:\dfrac{7}{12}\right).\dfrac{4}{5}=\left(\dfrac{157.3.4}{2.4.7}-\dfrac{53.3.4}{4.7}\right).\dfrac{4}{5}=\left(\dfrac{417}{14}-\dfrac{159}{7}\right).\dfrac{4}{5}=\dfrac{153}{14}.\dfrac{4}{5}=\dfrac{306}{35}\)