# Find the sum of the first 8 terms of the following sequence. -5, 15, -45, ...

## Question:

Find the sum of the first 8 terms of the following sequence.

-5, 15, -45, ...

## Geometric Sequences:

In mathematics, a geometric sequence is formed when each subsequent term is created by multiplying/dividing the previous term by a constant. This type of sequence can be written as {eq}a,ar,a{{r}^{2}},a{{r}^{3}},a{{r}^{4}},\cdots
{/eq} Here, *a* is the first term of the geometric sequence and *r* is the common ratio of the geometric sequence. When terms of the sequence are added together, a series is formed (the sum of a sequence).

## Answer and Explanation: 1

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View this answerWe are given the sequence {eq}-5,15,-45,\cdots~{/eq} and asked to find the sum of the first eight (8) terms.

First, we note that the given sequence...

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Chapter 12 / Lesson 6Define what a geometric series is and compare finite and infinite series. Using examples, learn the geometric series formula and how to solve geometric series.