I'm not sure this is how you are expected to solve this, or even if thisOriginally Posted bydelpin

is the simplest method; but:

First divide through by and rearrange to get:

Now this gives:

So there exists an integer such that:

Now the LHS (left hand side) is even, so must be odd.

So let , then:

But the LHS is divisible by so the RHS must also be divisible by

so must be even., so we may write it as , and then:

Now substituting this back into gives:

So we see that for any :

is a solution.

RonL