#### Answer

$x=\left\{ -\sqrt{10},\sqrt{10}\right\}$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
To solve the given equation, $
x^2-10=0
,$ express first in the form $x^2=c.$ Then take the square root of both sides.
$\bf{\text{Solution Details:}}$
Using the properties of equality, the given equation is equivalent to
\begin{array}{l}\require{cancel}
x^2=0+10
\\\\
x^2=10
.\end{array}
Taking the square root of both sides (Square Root Property), the equation above is equivalent to
\begin{array}{l}\require{cancel}
x=\pm\sqrt{10}
.\end{array}
Hence the solutions are $
x=\left\{ -\sqrt{10},\sqrt{10}\right\}
.$