Hello, to rationalize the denominator, you want to get rid of the radical at the bottom by mulitplying the top and the bottom by "1". The key to this problem is to notice the index of "6". If you attempted to solve it by using just the with an index of "2" you would get a different answer.
Let's first get our number "1"
Now we need to rationalize the denominator
The last step is to simplify the answer
Divide out the "y" and you should end up with your answer.
Oops...my bad, I should have given hints and not shown the whole problem. Sorry about that. I'm new on here and won't do that again. Though, there is typically more than one way to solve a problem. I highly encourage you to attempt simplifying the problem first and then solving it.