The formula that describes the sequence is 
Step-by-step explanation:
The nth-term formula for a geometric sequence is
, where
- a represents the first term of the sequence
- r signifies the common ratio between any two consecutive terms
= 
∵ The sequence is
, -4, -24, -144,.......
∵ The first term is 
∵ The second term is -4
∴ 
∵ The third term is -24
∴ 
∵ The fourth term is -144
∴ 
∵
=
=
= 6
∴ There is a consistent ratio between two consecutive terms
∴ The sequence qualifies as a geometric sequence
∵ The formula for the nth term of the geometric sequence is 
∵ a = 
∵ r = 6
∴ The equation for the sequence is 
The formula that can be employed to outline the sequence is 
Learn more:
You can explore more about sequences in