Break the numbers under the radical into perfect squares: [tex]\sqrt{2^2*2^2*2*x^2*x^2*z}[/tex]. Take the perfect squares out: you have two 2's, and 2 x's, on the outside of the radical with 2 and z leftover: [tex]3*2*2*x*x*\sqrt{2*z}[/tex] . Multiply everything together to get [tex]12x^2\sqrt{2z}[/tex].
