\(\left(x-1\right)^2=49\)
\(\left(x-1\right)^2=\left(\pm7\right)^2\)
\(\Rightarrow\begin{cases}x-1=7\\x-1=-7\end{cases}\)
\(\Rightarrow\begin{cases}x=7+1\\x=-7+1\end{cases}\)
\(\Rightarrow\begin{cases}x=8\\x=-6\end{cases}\)
Vậy \(x\in\left\{8;-6\right\}\)
Ta có: (x-1)\(^2\) = 49
(x-1) = \(\left(\pm7\right)^2\)
* x-1 = 7 => x = 7+1=8.
* x-1= -7 => x= -7+1 = -6.
Vậy x=8 hoặc x= -6.
\(\left(x-1\right)^2=49\)
\(\Rightarrow x-1=\pm7\)
+) \(x-1=7\Rightarrow x=8\)
+) \(x-1=-7\Rightarrow x=-6\)
Vậy \(x\in\left\{8;-6\right\}\)
\(\left(x-1\right)^2=49\)
\(\Rightarrow x-1=\pm7\)
\(\Rightarrow x\in\left\{8;-6\right\}\)
