We begin by plugging in 1 for n: <-- so the only possible correct choice so far is C, for none of the others have 1st term -3 But to make sure, let's plug in 2 for n: Uh oh! Something's wrong! The second term has to be 9, and none of the choices have 2nd term 9. Let's see what the correct answer would have to be. Let's plug in 3 for n: Let's plug in 4 for n: So the correct answer is -3, 9, -27, 81 So it's none of those listed. Edwin