Dễ mà bạn !
<=> \(\sqrt{\left(x-3\right)^2}\) =10
<=> |\(x-3\)|=10
(+) \(x-3\) =10<=> \(x=13\) (\(x-3\ge0\) )
(+) \(-\left(x-3\right)=10\) <=> 3-\(x\) =10 <=> x=-7(x-3<0)
\(\sqrt{x^2-6x+9}=10\)
\(\Leftrightarrow\left|x-3\right|=10\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=10\\3-x=10\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=13\\x=-7\end{matrix}\right.\)
Vậy \(x=13\) hoặc \(x=-7\)