\(\left(x-1\right)^2-1+x^2-\left(1-x\right)\left(x+3\right)=0\)
\(\Leftrightarrow\) \(x^2-2x+1-1+x^2-x-3+x^2+3x=0\)
\(\Leftrightarrow\) \(3x^2-3=0\)
\(\Leftrightarrow\) \(3\left(x^2-1\right)=0\)
\(\Leftrightarrow\) \(3\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}x-1=0\\x+1=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)
Vậy x = 1 hoặc x = -1.
x^2 -2x +1 -1 + x^2 - x + x^2 -3 +3x = 0
=> 3. x^2 -3 =0
=> 3 ( x^2 - 1) =0
=> ( x-1) ( x+1) =0
=> x=0 hoặc x= 1
Vậy : x= 0 hoặc x=1
\(\left(x-1\right)^2-1+x^2-\left(1-x\right)\left(x+3\right)=0\)
<=>\(x\left(x-2\right)+x^2-x-3+x^2+3x=0\)
<=>\(x^2-2x+2x^2+2x-3=0\)
<=>\(3x^2-3=0\Leftrightarrow3\left(x^2-1\right)=0\Leftrightarrow3\left(x-1\right)\left(x+1\right)=0\)
=> \(\left\{{}\begin{matrix}x-1=0\\x+1=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)
Vậy x = 1 hoặc -1
