Question 77775
<pre>
             {{{sqrt(16a^4x^2)}}} 

         {{{sqrt(2*2*2*2*a*a*a*a*x*x)}}}

      {{{sqrt( (2*2)(2*2) (a*a) (a*a)(x*x))}}}

      {{{sqrt( (2^2)(2^2)(a^2)(a^2)(x^2))}}}

           {{{sqrt(2^2)*sqrt(2^2)*sqrt(a^2)*sqrt(a^2)*sqrt(x^2))}}}

             {{{2*2*a*a*x}}}

             {{{4*a^2*x}}}

              {{{4a^2x}}}