How to show $\mathbb{E}[\frac{X}{X+Y}] = 1/2$ when X and Y are identically distributed but not necessarily independent.

Question

I am reviewing for a test and came across a question where I had to show $\mathbb{E}[\frac{X}{X+Y}] = 1/2$ when X, Y are identically distributed but not necessarily independent, and X, Y > 0. Clearly $\mathbb{E}[\frac{X}{X+Y}] +\mathbb{E}[\frac{Y}{X+Y}] = 1$ from linearity, but I’m not sure how it can be shown both expectations are equal when X,Y are not independent.