remember [tex] \sqrt{ \frac{x}{y} }= \frac{ \sqrt{x} }{ \sqrt{y} } [/tex]
and
[tex] \sqrt{ab}=( \sqrt{a})( \sqrt{b}) [/tex]
so
[tex] \sqrt{ \frac{100}{4x^2} }= \frac{ \sqrt{100} }{ \sqrt{4x^2} } = \frac{ 10 }{ (\sqrt{4})(\sqrt{x^2}) }= \frac{ 10 }{ (2)(x) } = \frac{ 10 }{ 2x }=\frac{ 5 }{ x }[/tex]
