Question 72
Find all functions $f: \mathbb{R} \rightarrow \mathbb{R}$ such that
$$
f(x+f(y))+x=f(f(2 x)+y)
$$
for all real $x$ and $y$.
$$
f(x+f(y))+x=f(f(2 x)+y)
$$
for all real $x$ and $y$.
MathNet 2020 — Math Olympiad Vault — Part 02 Question 72
Math Olympiad Vault · MathNet 2020 — Math Olympiad Vault — Part 02