Question 1208359
<pre>
It's a little longer this way, but maybe you can understand it better
this way:

{{{sqrt(4x^3*9y^5)}}}

Write what's under the square root as a product of the simplest factors
possible:

{{{sqrt(2*2*x*x*x*3*3*y*y*y*y*y)}}}

Now group as many pairs of like factors as possible:

{{{sqrt((2*2)*(x*x)*x*(3*3)*(y*y)*(y*y)*y))}}} 

Now realize that when a pair of like factors are multiplied,
that is that factor squared. So write every pair as a square

{{{sqrt((2^2)*(x^2)*x*(3^2)*(y^2)*(y^2)*y)}}} 

Now we take the square root of every one of those squares,
and since the square root undoes the square we have all
those outside the square root, and only the x and the y
that didn't pair up have to be left inside the square root:

{{{2*x*3*y*y*sqrt(x*y)}}}

or

{{{6xy^2*sqrt(xy)}}}

Edwin</pre>