If n is an integer, which of the following CANNOT be an even integer?
(A) 2n + 2
(B) n – 5
(C) 2n
(D) 2n + 3
Choose n to be 1.
Then 2 n + 2 = 2 ⋅1+ 2 = 4, which is even. So eliminate (A).
Next, n – 5 = 1 – 5 =–4. Eliminate (B).
Next, 2 n = 2 ⋅1 = 2 . Eliminate (C).
Next, 2 n + 3 = 2 ⋅1+ 3 = 5 is not even.Thus, choice (D).