# 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).