MathDB

Let

c>0

be a given positive real and

\mathbb{R}_{>0}

be the set of all positive reals. Find all functions

f \colon \mathbb{R}_{>0} \to \mathbb{R}_{>0}

such that f((c+1)x+f(y))=f(x+2y)+2cx \textrm{for all } x,y \in \mathbb{R}_{>0}.

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