Question 257216
This is a question about rationalizing a binomial denominator.  I am not sure how to get the -r out of the final equation without turning the 9 into a negative number also by simply multiplying both numerator and denominator by
-1.  Anyway, here is the problem I am trying to solve.

{{{ sqrt (r) }}} over 3 -{{{ sqrt (r) }}}

The answer I come up with is 3 {{{ sqrt (r) }}} +r over 9-r.
:
But that's right, you got rid of the radical in the denominator, that's all you can do