Which sequences are geometric? check all that apply.
a) –2.7, –9, –30, –100,
b) –1, 2.5, –6.25, 15.625,
c) 9.1, 9.2, 9.3, 9.4,
d) 8, 0.8, 0.08, 0.008,
f) 4, –4, –12, –20,

Geometric sequences are characterized by having a common ratio, r. It is calculated by getting the ratio of a(n+1) and a(n). We can determine which is the geometric sequence, if we calculate which sequence will have a common ratio. We do as follows:

A) –2.7, –9, –30, –100, ... 
-9/-2.7=10/3
-30/-9=10/3

B) –1, 2.5, –6.25, 15.625, ... 
2.5/-1=-2.5
-6.25/2.5=-2.5

C) 9.1, 9.2, 9.3, 9.4, ... 
9.2/9.1=92/91
9.3/9.2=93/92

D) 8, 0.8, 0.08, 0.008, ... 
0.8/8=1/10
0.08/0.8=1/10

F) 4, –4, –12, –20, ...
-4/4 = -1
-12/-4=3

Therefore, options A,B and D represents a geometric sequence.

1200 inches = 30 yards12 inches= 1 foot3 feet= 1 yard3feet= 36 inchesyou can set up a proportion then use inverse operations that looks sorry it looks so sloppy lol