Question

[Hoàng Kim Nhung]

tính

\(4\dfrac{1}{5}\times2\dfrac{1}{4}=\)                     \(3\dfrac{3}{5}\times1\dfrac{2}{3}=\)

\(4\dfrac{1}{5}:2\dfrac{1}{4}=\)                      \(3\dfrac{3}{5}:1\dfrac{2}{3}=\)

Answer 1

[⭐Hannie⭐]

`4 1/5 xx 2 1/4`

`= 21/5 xx 9/4`

`= 189/20`

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`4 1/5 : 2 1/4`

`= 21/5 : 9/4`

`= 21/5 xx 4/9`

`=84/45`

`=28/15`

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`3 3/5 xx 1 2/3`

`= 18/5 xx 5/3`

`= 90/15`

`=6`

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`3 3/5 : 1 2/3`

`= 18/5 : 5/3`

`= 18/5 xx 3/5`

`=54/25`

Answer 2

[Nguyễn Ngọc Thiện Nhân]

\(4\dfrac{1}{5}\times2\dfrac{1}{4}\\ =\dfrac{21}{5}\times\dfrac{9}{4}\\ =\dfrac{21\times9}{5\times4}\\ =\dfrac{189}{20}\)

\(3\dfrac{3}{5}\times1\dfrac{2}{3}\\ =\dfrac{18}{5}\times\dfrac{5}{3}\\ =\dfrac{18\times5}{5\times3}\\ =\dfrac{90}{15}\\ =6\)

\(4\dfrac{1}{5}:2\dfrac{1}{4}\\ =\dfrac{21}{5}:\dfrac{9}{4}\\ =\dfrac{21}{5}\times\dfrac{4}{9}\\ =\dfrac{21\times4}{5\times9}\\ =\dfrac{84}{45}\\ =\dfrac{28}{15}\)

\(3\dfrac{3}{5}:1\dfrac{2}{3}\\ =\dfrac{18}{5}:\dfrac{5}{3}\\ =\dfrac{18}{5}\times\dfrac{3}{5}\\ =\dfrac{18\times3}{5\times5}\\ =\dfrac{54}{25}\)