Answer:
Geometric sequences are below in bold.
Step-by-step explanation:
First one is 2/5, 2/10, 2/20, 2/40
2/10 = 2/5 * 1/2 ; 2/20 = 2/10 * 1/2
This is geometric with common ratio 1/2.
Second is 11/12, 8/12, 5/12, 2/12
This is not geometric It is arithmetic with common difference -3/12.
25, 19, 13, 7.... is arithmetic with d = -6
4, 12, 36, 108
12 = 3*4, 36 = 3*12 and so on
This is geometric with r = 3.
-5, 5, -5, 5,...
Each term is obtained from the prievious by multiplying by - 1. S
this is geometric with r = -1.
-3, 0, 3, 6 is arithmetic with d = 3.
-8, -2, 1/2, 1/8
This is not geometric as there is no common ratio.
