# An algebra prove question

by numberthree
Tags: algebra, prove
 P: 7 Have you thought about using mathematical induction? Set up your base case: n = 3 You will show that $$2^3-1 = 8 - 1 = 7$$ is prime and $$2^3 + 1 = 9$$ is not since $$9 = 3 \cdot 3$$. Assume that it's true for n. Then prove the case for n + 1.