Find the sum of the geometric series.
-4 - 8 + 16 - 32 + 64
A) -44
B) 44
C) 124
D) -124

Question

Quizplus · Accepted Answer

The series is a geometric series with the first term $a = 4$ and common ratio $r = -2$. The sum of the first $n$ terms of a geometric series is given by $S_n = \frac{a(1 - r^n)}{1 - r}$, where $n$ is the number of terms. Here, $n = 5$, so $S_5 = \frac{4(1 - (-2)^5)}{1 - (-2)} = \frac{4(1 + 32)}{3} = \frac{4 \times 33}{3} = 44$.

Find the Sum of the Geometric Series