Question 728530
(The 15th root of (the fourth root of(x^3))) 
<pre>
{{{root(15,root(4,x^3))}}}{{{""=""}}}

{{{matrix(2,2,"","",

(root(4,x^3))^(1/15),""="")


}}}

{{{matrix(2,2,"","",

(x^(3/4))^(1/15),""="")}}}

{{{matrix(2,2,"","",

x^(3/60),""="")
}}} You got this far.  Now what you do is reduce the
fraction exponent {{{3/60}}} to lowest terms {{{1/20}}}:

{{{matrix(2,2,"","",

x^(1/20),""="")
}}} 

Then you get this back into a root:

{{{root(20,x)}}}

Edwin</pre>