\(A=\dfrac{4}{7.31}+\dfrac{6}{7.41}+\dfrac{9}{10.41}+\dfrac{7}{10.57}\)
\(A=\dfrac{20}{35.31}+\dfrac{30}{35.31}+\dfrac{45}{50.41}+\dfrac{35}{50.57}\)
\(A=5.\left(\dfrac{4}{35.31}+\dfrac{6}{35.41}+\dfrac{9}{50.41}+\dfrac{7}{50.57}\right)\)
\(A=5.\left(\dfrac{1}{31}-\dfrac{1}{35}+\dfrac{1}{35}-\dfrac{1}{41}+\dfrac{1}{41}-\dfrac{1}{50}+\dfrac{1}{50}-\dfrac{1}{57}\right)\)
\(A=5.\left(\dfrac{1}{31}-\dfrac{1}{57}\right)\)
\(B=\dfrac{7}{19.31}+\dfrac{5}{19.43}+\dfrac{3}{23.43}+\dfrac{11}{23.57}\)
\(B=\dfrac{14}{34.31}+\dfrac{10}{38.43}+\dfrac{6}{46.43}+\dfrac{22}{46.57}\)
\(B=2.\left(\dfrac{7}{34.31}+\dfrac{5}{38.43}+\dfrac{3}{46.43}+\dfrac{11}{46.57}\right)\)
\(B=2.\left(\dfrac{1}{31}-\dfrac{1}{34}+\dfrac{1}{34}-\dfrac{1}{43}+\dfrac{1}{43}-\dfrac{1}{46}+\dfrac{1}{46}-\dfrac{1}{57}\right)\)
\(B=2.\left(\dfrac{1}{31}-\dfrac{1}{57}\right)\)
\(\Rightarrow\dfrac{A}{B}=\dfrac{5.\left(\dfrac{1}{31}-\dfrac{1}{57}\right)}{2.\left(\dfrac{1}{31}-\dfrac{1}{57}\right)}\)
\(\Rightarrow\dfrac{A}{B}=\dfrac{5}{2}\)