Prove: The difference between the product of two distinct prime numbers and their sum must be odd.
I attempted to disprove the hypothesis by finding two distinct primes:
$i, k$ where $(i \cdot k ) - (i - k) \equiv 2n $
As I have not been able to find a pair of primes to satisfy my equality, should I instead be trying to prove with a contrapositive or contradiction? If so how would go about changing the original statement.