Answer and explanation:
Given two natural numbers n and n+3, we prove that the difference or their squares is even thus:
(n+3)²-(n)²= (n+3)(n+3)-(n)²
=n²+3n+3n+9-n²
=6n+9
Since the value of the difference of square of the natural numbers n and n+3 is in the form 6n+9, the difference is not an even number.
