I'm not a very logical person, and I would hardly consider math a strength so, I'm stuck with these proofs: 1. Prove that every positive integer, ending in 5 creates a number that when squared, ends in 25 2. Prove that if n is an even positive integer, then n^3 - 4n is always divisible by 48. 3. Prove that the square of an odd integer is always of the form 8k + 1 , where k is an integer. Thank you.