Question

Answer 1

a) \(\dfrac{1}{7}:\dfrac{-6}{21}=\dfrac{1}{7}\times\dfrac{-21}{6}=\dfrac{-1}{2}\)

b) \(-2\dfrac{1}{2}:\dfrac{10}{7}-25\%=\dfrac{-5}{2}\times\dfrac{7}{10}-25\%=\dfrac{-35}{20}-\dfrac{25}{100}=\dfrac{-175}{100}-\dfrac{25}{100}=\dfrac{-200}{100}=-2\)

c) \(\dfrac{3}{11}\times\dfrac{5}{9}+\dfrac{12}{11}\times\dfrac{5}{9}-\dfrac{5}{9}\times\dfrac{4}{11}=\dfrac{5}{9}\left(\dfrac{3}{11}+\dfrac{12}{11}-\dfrac{4}{11}\right)=\dfrac{5}{9}\times1=\dfrac{5}{9}\)

Chúc bạn học tốt