Question

Find the 9th term of the following geometric sequence: 1, –3, 9, –27. A. –2,456 B. 6,561 C. –5,661 D. 7,241

Answer 1

Geometric sequence: 1, -3, 9, -27...

Here, first term' a = 1
Common ratio, r = -3/1 = -3

9th term = a × r^(9-1) = a × r^8 = 1 × (-3)^8 = 6561

Your answer is B.