Subject: Discrete Mathematics and its Application. Please help solve and provide a clear explanation and analysis. In order for me to understand it a lot better. Thank you We define an integer k to be even if k = 2j for some integer j, and we define an integer k to be odd if k = 2j + 1 for some integer j. Prove, using these definitions, that for any integer n, the expression n2 2n + 5 is even if and only if n is odd