This question already has an answer here:
For all integers $x$ and $y$, if $x^3 + x = y^3 + y$ then $x = y$.
This is what I have done so far:
Proof: Suppose $x$ and $y$ are arbitrary integers. We know that $x^3 + x = y^3 + y$, we want to prove that $x = y$.
So, this is logically making sense, so it is true. any hints please?