Question

(3x - 5) ^4 = 256

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Answer 1

`(3x-5)^4=256`

`=>(3x-5)^4=(4)^4=(-4)^4`

`=>[(3x-5=4),(3x-5=-4):}`

`=>[(3x=9),(3x=1):}`

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

Vậy `x=3` hoặc `x=1/3.`

Answer 2

Ta có: \(\left(3x-5\right)^4=256\)

\(\Leftrightarrow\left[{}\begin{matrix}3x-5=4\\3x-5=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=9\\3x=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=\dfrac{1}{3}\end{matrix}\right.\)