Question 50
Let $f$ be a real-valued function such that
$$
f(x-f(y))=f(x)-x f(y)
$$
for any real numbers $x$ and $y$. If $f(0)=3$, determine $f(2016)-f(2013)$.
$$
f(x-f(y))=f(x)-x f(y)
$$
for any real numbers $x$ and $y$. If $f(0)=3$, determine $f(2016)-f(2013)$.