Question

1)Rút gọn:

a) \(\frac{9^{14}\times25^5\times8^7}{18^{12}\times625^3\times24^3}\)

b)\(\frac{71\times52+53}{530\times71-180}\)

2)CMR:

\(\frac{abab}{cdcd}=\frac{ababab}{cdcdcd}\)

3)Tính hợp lí:

\(A=\frac{1}{3}-\frac{3}{4}-\left(\frac{-3}{5}-\frac{1}{57}+\frac{1}{36}+\frac{-1}{15}\right)-\frac{2}{9}\)

 

Answer 1

1) 

a) \(\frac{9^{14}.25^5.8^7}{18^{12}.625^3.24^3}=\frac{3^{28}.5^{10}.2^{21}}{2^{21}.3^{24}.5^{12}.3^3.2^9}=\frac{3}{5^2}=\frac{3}{25}\)

Answer 2

Bài 2:

\(\frac{abab}{cdcd}=\frac{ab.101}{cd.101}=\frac{ab}{cd};\frac{ababab}{cdcdcd}=\frac{ab.10101}{cd.10101}=\frac{ab}{cd}\)

Vậy \(\frac{ab}{cd}=\frac{abab}{cdcd}=\frac{ababab}{cdcdcd}\)