<=> x2 - 2x + 4x - 8 - 2 = 0
<=> x2 + 2x - 10 = 0
<=> (x + 1)2 = 11 => \(\orbr{\begin{cases}x+1=\sqrt{11}\\x+1=-\sqrt{11}\end{cases}\leftrightarrow\orbr{\begin{cases}x=\sqrt{11}-1\\x=-\sqrt{11}-1\end{cases}}}\)
Vậy ...
\(\Rightarrow x^2-2x+4x-8=2\)
\(\Rightarrow x^2-2x+4x=10\)
\(\Rightarrow x\left(x-2+4\right)=10\)