Cross multiply.
\[(2+\sqrt{3})(2-\sqrt{3})=xx\]
Use Difference of Squares: \({a}^{2}-{b}^{2}=(a+b)(a-b)\).
\[{2}^{2}-{\sqrt{3}}^{2}=xx\]
Simplify \({2}^{2}\) to \(4\).
\[4-{\sqrt{3}}^{2}=xx\]
Use this rule: \({\sqrt{x}}^{2}=x\).
\[4-3=xx\]
Use Product Rule: \({x}^{a}{x}^{b}={x}^{a+b}\).
\[4-3={x}^{2}\]
Simplify \(4-3\) to \(1\).
\[1={x}^{2}\]
Take the square root of both sides.
\[\pm \sqrt{1}=x\]
Simplify \(\sqrt{1}\) to \(1\).
\[\pm 1=x\]
Switch sides.
\[x=\pm 1\]
x=1,-1
