Question 292630
You can write is as 
{{{15^(1/3)/3^(1/3)}}} "The cube root of 15 divided by the cube root of 3"
{{{15^(1/3)/3^(1/3)=(3*5)^(1/3)/3^(1/3)}}} 
{{{15^(1/3)/3^(1/3)=cross((3)^(1/3))*(5)^(1/3)/cross(3^(1/3))}}} 
{{{15^(1/3)/3^(1/3)=(5)^(1/3)}}}