Question

Answer 1

\(PT\Leftrightarrow\left|x-6\right|=5\Leftrightarrow\left[{}\begin{matrix}x-6=5\\6-x=5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=11\\x=1\end{matrix}\right.\)

Answer 2

\(\sqrt{x^2-12x+36}=5\)

\(\sqrt{\left(x^2-2.x.6+6^2\right)}=5\)

\(\sqrt{\left(x-6\right)^2}=5\)

⇔\(\left(x-6\right)^2=25\)

⇔\(\left[{}\begin{matrix}x-6=5\\x-6=-5\end{matrix}\right.\)

⇔\(\left[{}\begin{matrix}x=11\\x=1\end{matrix}\right.\)