Tìm tỉ số \(\frac{A}{B}\) biết:
a) \(A=\frac{4}{31.7}+\frac{6}{7.41}+\frac{9}{10.41}+\frac{7}{10.57}\) ; \(B=\frac{7}{19.31}+\frac{5}{19.43}+\frac{3}{23.43}+\frac{11}{23.57}\)
b) \(A=\frac{40}{31.39}+\frac{35}{39.46}+\frac{30}{46.52}+\frac{25}{52.57}\); \(B=\frac{91}{19.31}+\frac{65}{19.43}+\frac{39}{23.43}+\frac{143}{69.19}\)