Question

Tính : Kết quả là một phân số tối giản 

a, \(\dfrac{8x4x50}{48x75}\) 

b, \(\dfrac{7x9x81}{9x3x5x84}\)

Answer 1

a: \(=\dfrac{32}{48}\cdot\dfrac{50}{75}=\dfrac{2}{3}\cdot\dfrac{2}{3}=\dfrac{4}{9}\)

b: \(=\dfrac{7\cdot9\cdot81}{27\cdot5\cdot84}=\dfrac{9\cdot81}{27\cdot3}\cdot\dfrac{7}{5\cdot28}=9\cdot\dfrac{1}{4\cdot5}=\dfrac{9}{20}\)

Answer 2

\(a,\dfrac{8\times4\times50}{48\times75}=\dfrac{2\times2\times2\times2\times2\times25}{2\times2\times2\times2\times3\times25\times3}=\dfrac{2\times2}{3\times3}=\dfrac{4}{9}\)

\(b,\dfrac{7\times9\times81}{9\times3\times5\times84}=\dfrac{7\times9\times9\times3\times3}{9\times3\times5\times7\times3\times4}=\dfrac{9}{5\times4}=\dfrac{9}{20}\)

Answer 3

b,7×9×819×3×5×84=7×9×9×3×39×3×5×7×3×4=95×4=920