Which expression is equivalent to the given expression? Assume the denominator does not equal zero.

https://app.edmentum.com/mimetex/mimetex?\fs3%5Cfrac%7B14x%5E%7B4%7Dy%5E%7B6%7D%7D%7B7x%5E%7B8%7Dy%5E%7B2%7D%7D