\(A=7-\dfrac{3}{4}+\dfrac{1}{3}-6-\dfrac{5}{4}+\dfrac{4}{3}-5+\dfrac{7}{4}-\dfrac{5}{3}\\ =\left(7-6-5\right)+\left(-\dfrac{3}{4}-\dfrac{5}{4}+\dfrac{7}{4}\right)+\left(\dfrac{1}{3}+\dfrac{4}{3}-\dfrac{5}{3}\right)\\ =-4-\dfrac{1}{4}+0=-\dfrac{17}{4}\)
\(B=\dfrac{1}{3}.\left(-\dfrac{4}{5}+\dfrac{-6}{5}\right)=\dfrac{1}{3}.\left(-\dfrac{10}{5}\right)=\dfrac{1}{3}.\left(-2\right)=-\dfrac{2}{3}\)
\(C=\dfrac{1}{7}.3.\dfrac{9}{13}.\dfrac{1}{2}-\dfrac{1}{14}.\dfrac{1}{13}=\dfrac{1}{14}.\dfrac{27}{13}-\dfrac{1}{14}.\dfrac{1}{13}\\ =\dfrac{1}{14}.\left(\dfrac{27}{13}-\dfrac{1}{13}\right)=\dfrac{1}{14}.2=\dfrac{1}{7}\)
\(D=\left(-\dfrac{7}{20}\right).\dfrac{7}{3}+\left(\dfrac{7}{20}\right).\dfrac{7}{3}=\left(-\dfrac{7}{20}+\dfrac{7}{20}\right).\dfrac{7}{3}=0.\dfrac{7}{3}=0\)
\(E=\dfrac{7}{8}:\left(\dfrac{1}{6}\right)+\dfrac{7}{8}:\left(-\dfrac{7}{18}\right)=\dfrac{7}{8}.6+\dfrac{7}{8}.\left(-\dfrac{18}{7}\right)=\dfrac{7}{8}.\left(6+\dfrac{-18}{7}\right)\\ =\dfrac{7}{8}.\dfrac{24}{7}=3\)
