For example if I have some complicated expression (all variables are positive integers) but I want to multiply everything out so there are no denominators and then rearrange so that it is equal to 0, is there a flattening function for this?
To provide an example:
$$x/y + x/y^2 + x/y^3 + x/y^4 = 4/x$$
I want to force it into form
$$x^2y^3 + x^2y^2 + x^2y + x^2 - 4y^4 = 0$$