Question 896059

You might be starting with this:
{{{sqrt(3/7x)+- 9}}}


The 9 is already rational needing no treatment.


{{{sqrt(3/7x)=sqrt(3)/sqrt(7x)}}}
{{{(sqrt(3)/sqrt(7x))(sqrt(7x)/sqrt(7x))}}}
{{{highlight(sqrt(21x)/(7x))}}}