Prove that the number 5 0 + 5 1 + 5 2 is an irrational number. For this problem you cannot assume that any number is irrational to begin with. You MUST use the approach described in class (i.e., you cannot use prime factorization) and your solution MUST include a lemma demonstrating that if 2 is divisible by 5 then is divisible by 5.