Answer:
The next term is - 2 ⇒ last answer
Step-by-step explanation:
∵ The sequence is 54 , -18 , 6 , ......
∵ -18 ÷ 54 = 
∵ 6 ÷ -18 = 
- There is a constant ratio between each two consecutive terms
∴ The sequence is a geometric sequence
The nth rule of the geometric sequence is
, where
- a is the first term
- r is the constant ratio between each two consecutive terms
∵ The first term = 54
∴ a = 54
∵ The constant ratio = 
∴ r = 
∵ The next term is the fourth term
∴ n = 4
- Substitute a, r and n in the rule above
∴ 
∴
∴ 
∴ 
The next term is - 2