Question

\(\dfrac{2}{5}\)x\(\dfrac{5}{7}\)x\(\dfrac{7}{9}\):\(\dfrac{1}{9}\)=...

Answer 1

cần đáp án

Answer 2

=2

Answer 3

\(=\dfrac{2}{7}\cdot\dfrac{7}{9}\cdot9=2\)

Answer 4

2

Answer 5

\(\dfrac{2}{5}\times\dfrac{5}{7}\times\dfrac{7}{9}:\dfrac{1}{9}\)

\(=\dfrac{2\times5}{5\times7}\times\dfrac{7}{9}:\dfrac{1}{9}\)

\(=\dfrac{2\times1}{1\times7}\times\dfrac{7}{9}:\dfrac{1}{9}\)

\(=\dfrac{2}{7}\times\dfrac{7}{9}:\dfrac{1}{9}\)

\(=\dfrac{2\times7}{7\times9}:\dfrac{1}{9}\)

\(=\dfrac{2\times1}{1\times9}:\dfrac{1}{9}\)

\(=\dfrac{2}{9}:\dfrac{1}{9}\)

\(=\dfrac{2}{9}\times\dfrac{9}{1}\)

\(=\dfrac{2\times9}{9\times1}\)

\(=\dfrac{2\times1}{1\times1}\)

\(=\dfrac{2}{1}\)

\(=2\)

Answer 6

\(\dfrac{2}{5}\cdot\dfrac{5}{7}\cdot\dfrac{7}{9}\cdot9=2\)