Question

tính nhanh

\(\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4}{5}.\dfrac{82}{7}\)

Answer 1

Có:

\(\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4}{5}.\dfrac{82}{7}\)

\(=\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4.82}{5.7}=\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4.82}{7.5}=\dfrac{4}{7}.\dfrac{89}{5}-\dfrac{4}{7}.\dfrac{89}{5}\)

\(=\dfrac{4}{7}.\left(\dfrac{89}{5}-\dfrac{82}{5}\right)=\dfrac{4}{7}.\dfrac{7}{5}=\dfrac{4}{5}\)

Chúc bạn học tốt!

Answer 2

\(\dfrac{4}{7}\) .\(\dfrac{89}{5}\) - \(\dfrac{4}{5}\). \(\dfrac{82}{7}\)

= \(\dfrac{4.89}{7.5}\) - \(\dfrac{4}{5}\) . \(\dfrac{82}{7}\)= \(\dfrac{4}{5}\) .\(\dfrac{89}{7}\) - \(\dfrac{4}{5}\) . \(\dfrac{82}{7}\)= \(\dfrac{4}{5}\)\(\left(\dfrac{89}{7}-\dfrac{82}{7}\right)\)= \(\dfrac{4}{5}\). 1= \(\dfrac{4}{5}\)

Answer 3

- Mấy câu này giống trong đề cương của mình