\(\left(x-1\right)^2=4\)
\(\Rightarrow\left[{}\begin{matrix}x-1=\sqrt{4}\\x-1=-\sqrt{4}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=2\\x-1=-2\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)
\(\left(x-1\right)^2=4\Leftrightarrow x-1=2\Leftrightarrow x=3\)
\(\left(x-1\right)^2-4=0\)
\(\Leftrightarrow\left(x-1\right)^2-2^2=0\)
\(\Leftrightarrow\left(x-1-2\right)\left(x-1+2\right)=0\)
\(\Leftrightarrow\left(x-3\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\x+1=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)
Vậy \(x=-1\) hoặc \(x=3\)
\(\left(x-1\right)^2=4\)
\(\Leftrightarrow\left(x-1\right)^2=2^2\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=2\\x-1=-2\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)
Vậy x = 3 hoặc -1
