Given:
The geometric sequence is:

1 -4
2 20
3 -100
To find:
The explicit formula and list any restrictions to the domain.
Solution:
The explicit formula of a geometric sequence is:
...(i)
Where, a is the first term, r is the common ratio and
.
In the given sequence the first term is -4 and the second term is 20, so the common ratio is:



Putting
in (i), we get
where 
Therefore, the correct option is B.
Answer: i THINK it might be c
Step-by-step explanation: dont hold me to it tho. its just a guess. typed all of the equations in desmos but none of them came out exact. sorry love
Answer:
33 gallons
Step-by-step explanation:
44/20 = 2.2
$2.2 per gallon
2.2x15