Identify which of the following sequences is a geometric sequence. Check all that apply.
-48, 96, -192, 384, ...
1, 4, 9, 16, ...
3, 9, 27, 81, ...
5, 10, 20, 40, ...
24, 20, 16, 12, ...
25, 20, 15, 10, ...
-48, 96, -192, 384, ...
3, 9, 27, 81, ...