Use the Formula for the Sum of the First n Terms of a Geometric Sequence
-Find the sum of the first 11 terms of the geometric sequence: -4, -12, -36, -108, -324, . . . .
A)-354,292
B)-354,312
C)-354,255
D)-354,290

Question

Quizplus · Accepted Answer

The first term is -4 and the common ratio is -3. So, the sum of the first 11 terms is:S11 = -4(1 - (-3)^11) / (1 - (-3))= -4(1 - (-3)^11) / 4= -4(1 - (-3)^11)= -4(1 - 177147)= -4(-177146)= 708584= -354,292

Use the Formula for the Sum of the First N