I am having the following problem:
We have the unknowns x and y for which we know the following:
x/(x+y) = k where k is a real known number. We also have some known variables a and b which are real numbers and each one of them is less than x and y.
Is there a possible way to expand the following expression into a series or a mathematical approximation with x and y separated from a and b?
(x+a)/(x+y+a+b)
For example something like: k/(a+b)+2*k/(a+b)+...
In other words, would it be possible to know an approximate result of this expression without ever knowing x and y?