# How do you determine if -10,20,-40,80 is an arithmetic or geometric sequence?

##### 1 Answer

Jun 27, 2015

**The sequence is a geometric sequence.**

#### Explanation:

- In an Arithmetic sequence there is a common difference
#d# between any two consecutive terms - In a Geometric sequence there is a common ratio
#r# for any two consecutive terms

The sequence given is :

1) Checking if the sequence is an arithmetic sequence:

As observed

2) Checking if the sequence is a geometric sequence:

Since

**So the sequence is a geometric sequence.**