Question

giai pt: 3x² - 7x + 4=0

Answer 1

\(3x^2-7x+4=0.\\ \Leftrightarrow\left(x-\dfrac{4}{3}\right)\left(x-1\right)=0.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{4}{3}.\\x=1.\end{matrix}\right.\)

Answer 2

`= 3(x^2 - 7/3 x + 4/3) = 0`.

`= 3(x^2 - 2 . 7/6 + 49/36 - 1/36) = 0`

`= 3(x-1/6)^2 = 1/12`.

`=> (x-1/6)^2 = 1/4 = (+-1/2)^2`.

`=> x = -1/3` hoặc `2/3`.

Answer 3

`3x^2-7x+4=0`

`<=>3x^2-3x-4x-4=0`

`<=>3x(x-1)-4(x-1)=0`

`<=>(x-1)(3x-4)=0`

`<=>[(x-1=0),(3x-4=0):}`

`<=>[(x=1),(x=4/3):}`

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