You can just substitute in here. For instance with the first pair, if x = 7, then 3(7) - 2 = 19; and 19 is not the y given. Try (B) and you get 3(1) - 2 = 1, not -1. No go. So (C) says 3(4) - 2 = 10, not 2. It must be (D), but try it to make sure. 3(2) - 2 = 4. Bingo.
