I'm trying to solve this task:
Find all functions $f:\mathbb{R} \to \mathbb{R}$ that satisfy: $(x-2)f(y)+f(y+2f(x)) = f(x + yf(x))$
I plugged in $x=2$:
$f(y + 2f(2)) = f(2 + yf(2))$
If I assume that values are equal:
$y + 2f(2) = 2 + yf(2)$
Then I get:
$f(2) = 1$
So then I randomly checked $f(x) = x - 1$ and it turned out to be a solution.
I then tried some other things but didn't really get anything.
Could somebody please give a hint as to how to find other solutions?
Thanks in advance.
EDIT: found this question