`(x+1)^2 +(2x-4)(x+1)=0`
`<=> (x+1)(x+1+2x-4)=0`
`<=>(x+1)(3x-3)=0`
\(< =>\left[{}\begin{matrix}x+1=0\\3x-3=0\end{matrix}\right.\\ < =>\left[{}\begin{matrix}x=-1\\x=1\end{matrix}\right.\)
\(\left(x+1\right)^2+\left(2x-4\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(x+1+2x-4\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(3x-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+1=0\\3x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\3x=3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=1\end{matrix}\right.\)
\(\text{Vậy phương trình có tập nghiệm là }S=\left\{\pm1\right\}\)
