Answer:
To solve this problem you must apply the proccedure shown below:
1. You have:
1) 128, 32, 8, 2 ,..
32/128=0.25
8/32=0.25
2/8=0,25
b. Geometric, common ratio is 0.25
2) 1, 3, 9, 27,...
3/1=3
9/3=3
27/9=3
c. Geometric, common ratio is 3
3) 5, 10, 15, 20,...
10-5=5
15-10=5
20-15=5
d. Arithmetic, common difference is 5.
4) 20, 17, 14, 11,...
a. Arithmetic, common difference is 3
Explanation: