#### Answer

$x=\pm\sqrt{b}$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
To find the solutions of the given equation, $
x^2-b=0
,$ use the properties of equality to express the given equation in the form $x^2=c.$ Then take the square root of both sides (Square Root Property).
$\bf{\text{Solution Details:}}$
Using the properties of equality, in the form $x^2=c,$ the given equation is equivalent to
\begin{array}{l}\require{cancel}
x^2=b
.\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{b}
.\end{array}