# How do you find the common ratio of the geometric sequence 7,-14,28,-56?

Jul 1, 2017

$r = - 2$

#### Explanation:

$\text{the common ratio r of a geometric sequence is}$

r=(a_2)/(a_1)=(a_3)/(a_2)=........ =a_n/(a_(n-1)

$\text{here } {a}_{1} = 7 , {a}_{2} = - 14$

$\Rightarrow r = \frac{- 14}{7} = - 2$