Find the 25th term of an arithmetic sequence whose first term is 12 and whose common difference is ‒6. A.‒144 B.132 C.‒132 D.156

Answer 1

we need to apply the common difference 24 times to get from our first term to our 25th term (25 -1 = 24). We simply use the formula a1 + 24*CD = a25, or 12 + 24*(-6) = 12 - 144 = -132.

Answer: C. -132