Complex affine ./ real affine

Screenshot_20210708_232035720×1280 339 KB

I am trying with equation 27. And read all possible material related to it. Still am not finding the solution.

Kindly help how to deal.

x*log2(1+y/x) = -rel_entr(x,x+y)/log(2)

Thank you Sir for your kind help… I will try this solution.