First, it appears that you are not using parentheses to state your problem correctly. Second, I have no clue what you mean by a converter.

Is this your problem

$Simplify\ \left(\dfrac{8}{x + y} + \dfrac{1}{4}\right) \div \left(\dfrac{x}{x + y} - 1\right).$

If so, the first step is to change each expression in parentheses into a single fraction. What do you get for each one?

Now when you divide a fraction by a fraction, how do you proceed?

So now what do you have?

And that simplifies nicely to what?