Question

\(\left(x+1\right)^2=4\left(x^2-2x+1\right)^2\)

Answer 1

`(x+1)^2=4(x^2-2x+1)^2`

`<=> (x+1)^2=[2(x-1)]^2`

`<=> (x+1)^2=(2x-2)^2`

`<=> (x+1+2x-2)(x+1-2x+2)=0`

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

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

Vậy `S={1/3 ; 3}`.