Answer
{$4-\sqrt {15},4+\sqrt {15}$}
Work Step by Step
Given: $x^2-8x+1=0$
This can be re-written as: $x^2-8x=-1$
We need to add $(-4)^2$ to complete the square.
Thus,
$x^2-8x+16=-1+16$
or, $(x-4)^2=15$
or, $(x-4)=\pm \sqrt {15}$
or, $x=4- \sqrt {15},4+\sqrt {15}$
Hence, solution set is $x=${$4-\sqrt {15},4+\sqrt {15}$}