Let n be an integer. Prove that n^2 - 3n + 9 is odd.
Added by Nieves W.
Step 1
Let's consider both cases for n. Case 1: n is even. If n is even, then n can be written as 2k, where k is an integer. Now let's substitute this into the expression: (2k)^2 - 3(2k) + 9 = 4k^2 - 6k + 9 Now, we can factor out a 2 from the first two terms: 2(2k^2 Show more…
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