We are given a statement based around positive integer numbers. In other words, we can consider them as natural numbers.
Since we have a statement based on natural numbers, we can use Mathematical induction to prove it's true.
This is done following these steps:
1. We prove that the statement is true for the first possible natural number. In this case, since we are told it has to work for positive integers, we prove that it is true for n=1.
2. We assume the statement is true for a certain minduction hypotesis.
3. Using the induction hypotesis, we prove that the statement is true for m+1.
4. If we can prove that the statement is true for m+1, then we conclude that the statement is true for any natural number n greater or equal to 1.