Question

Tính nhanh

\(A=\dfrac{4}{9}.19\dfrac{1}{4}-\dfrac{4}{9}.29\dfrac{1}{4}\)

Answer 1

`A = 4/9 . 19 1/4 - 4/9 .29 1/4`

`A = 4/9 . ( 19 1/4 - 29 1/4)`

`A = 4/9 .` \(\left[\left(19-29\right)+\left(\dfrac{1}{4}-\dfrac{1}{4}\right)\right]\)

`A = 4/9 . (-10)`

`A = (-40)/9`

Answer 2

\(=\dfrac{4}{9}.\left(19\dfrac{1}{4}-29\dfrac{1}{4}\right)\)

\(=\dfrac{4}{9}.-10\)

\(=\dfrac{-40}{9}\)

Answer 3

\(A=\dfrac{4}{9}.\left(19\dfrac{1}{4}-29\dfrac{1}{4}\right)=\dfrac{4}{9}.\left(-10\right)=-\dfrac{40}{9}\)

Answer 4

`4/9 * 19 1/4 - 4/9 * 29 1/4`

`= 4/9*(19 1/4 - 29 1/4)`

`= 4/9 * (-10)

`=-40/9`