(x-1)^2 - 2x(x-2)=(x-3)(x+3)
[tex]\it (x-1)^2 - 2x(x-2) = (x-3)(x+3) \Rightarrow
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\Rightarrow x^2-2x+1-2x^2+4x = x^2- 9 \Rightarrow - x^2+2x+1 = x^2- 9 \Rightarrow
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\Rightarrow - x^2+2x+1 - x^2+ 9 =0 \Rightarrow -2x^2+2x+10 = 0|_{\cdot(-1)} \Rightarrow
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\Rightarrow 2x^2-2x-10=0|_{:2} \Rightarrow x^2-x-5=0
[/tex]
[tex]\it \Delta = b^2-4ac \Rightarrow \Delta = 1+20 = 21
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x_{1,2} = \dfrac{-b \pm \sqrt{\Delta}}{2a} = \dfrac{1\pm\sqrt{21}}{2}\Rightarrow \begin{cases} \it x_{1} = \dfrac{1 - \sqrt{21}}{2}
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\it x_{2} = \dfrac{1 + \sqrt{21}}{2}
\end{cases}[/tex]