Câu hỏi của 22- Nhật Minh 6/5

a: \(=\dfrac{-22}{7}:\dfrac{-55}{49}=\dfrac{22}{7}\cdot\dfrac{49}{55}=\dfrac{2}{5}\cdot7=\dfrac{14}{5}\)b: \(=\dfrac{13}{3}:\dfrac{-15}{4}=\dfrac{13}{3}\cdot\dfrac{-4}{15}=\dfrac{-52}{45}\)c: \(=-\dfrac{9}{5}\cdot\dfrac{3}{4}=\dfrac{-27}{20}\)d: \(=9\cdot\dfrac{-1}{729}+\dfrac{1}{3}=\dfrac{-1}{81}+\dfrac{1}{3}=\dfrac{-1+27}{81}=\dfrac{26}{81}\)Câu trả lời: a: \(=\dfrac{-22}{7}:\dfrac{-55}{49}=\dfrac{22}{7}\cdot\dfrac{49}{55}=\dfrac{2}{5}\cdot7=\dfrac{14}{5}\)b: \(=\dfrac{13}{3}:\dfrac{-15}{4}=\dfrac{13}{3}\cdot\dfrac{-4}{15}=\dfrac{-52}{45}\)c: \(=-\dfrac{9}{5}\cdot\dfrac{3}{4}=\dfrac{-27}{20}\)d: \(=9\cdot\dfrac{-1}{729}+\dfrac{1}{3}=\dfrac{-1}{81}+\dfrac{1}{3}=\dfrac{-1+27}{81}=\dfrac{26}{81}\)