Đặt \(x^2-2x=a\)
\(\Rightarrow a^2+3a=-2\Leftrightarrow a^2+3a+2=0\)
\(\Rightarrow\left[{}\begin{matrix}a=-1\\a=-2\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x^2-2x=-1\\x^2-2x=-2\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x^2-2x+1=0\\x^2-2x+2=0\left(vn\right)\end{matrix}\right.\)
\(\Rightarrow x=1\)
Đặt x2−2x=a
⇒a2+3a=−2⇔a2+3a+2=0
⇒[a=−1a=−2 ⇒[x2−2x=−1x2−2x=−2 ⇒[x2−2x+1=0x2−2x+2=0(vn)