[tex]\displaystyle \bf\\
(x- \sqrt{5} )^2 = 20~~~\Big| \sqrt{~~~} \\\\
\sqrt{(x- \sqrt{5} )^2} = \sqrt{20}\\\\
\sqrt{(x- \sqrt{5} )^2} = \sqrt{4\cdot 5}\\\\
x- \sqrt{5} = \Big|2\sqrt{5} \Big|\\\\
x- \sqrt{5} = \pm 2\sqrt{5} \\\\
x = \sqrt{5} \pm 2\sqrt{5} \\\\
x_1 = \sqrt{5} + 2\sqrt{5} = \boxed{3\sqrt{5} }\\\\
x_2 = \sqrt{5} - 2\sqrt{5} = \boxed{-\sqrt{5} }\\\\
[/tex]