Question

Tính 2/5 : 4/7 : 8/9 . 6/8 . 9/2

Answer 1

\(\dfrac{2}{5}:\dfrac{4}{7}:\dfrac{8}{9}.\dfrac{6}{8}.\dfrac{9}{2}=\dfrac{2}{5}.\dfrac{7}{4}.\dfrac{9}{8}.\dfrac{6}{8}.\dfrac{9}{2}=\dfrac{2.7.9.6.9}{5.4.8.8.2}=\dfrac{6804}{2560}=\dfrac{1701}{640}.\)

Answer 2

\(=\dfrac{2}{5}\cdot\dfrac{7}{4}\cdot\dfrac{9}{8}\cdot\dfrac{6}{8}\cdot\dfrac{9}{2}=\dfrac{1701}{640}\)

Answer 3

\(=\dfrac{2}{5}\cdot\dfrac{7}{4}\cdot\dfrac{9}{8}\cdot\dfrac{6}{8}\cdot\dfrac{9}{2}\\ =\dfrac{2\cdot7\cdot9\cdot6\cdot9}{5\cdot4\cdot8\cdot8\cdot2}=\dfrac{6804}{2560}\)