Answer
$x=8$
Work Step by Step
Using $x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$ or the Quadratic Formula, the solution/s of the given quadratic equation, $
x^2-16x+64=0
,$ is/are
\begin{array}{l}\require{cancel}
x=\dfrac{-(-16)\pm\sqrt{(-16)^2-4(1)(64)}}{2(1)}
\\\\
x=\dfrac{16\pm\sqrt{256-256}}{2}
\\\\
x=\dfrac{16\pm\sqrt{0}}{2}
\\\\
x=\dfrac{16\pm0}{2}
\\\\
x=\dfrac{16}{2}
\\\\
x=8
.\end{array}