If (a=-9) and (d=6), what are the first four terms?

Correct answer: (-9, -3, 3, 9)

In an arithmetic progression, each new term is obtained by adding the common difference d to the previous term. Here, a = -9 and d = 6: -9, -9+6 = -3, -3+6 = 3, and 3+6 = 9. Therefore, the first four terms are (-9, -3, 3, 9). Option D subtracts 6 each time, so its common difference is -6. Exam tip: check the difference between consecutive terms to verify an AP.