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:
$109 and 35%
Step-by-step explanation:
49.05 is the sale price and the discount is 55%. What’s the original price?
price/ 1- discount
49.05/ 1 - 0.55
49.05/ 0.45
109
for the other part
to find the discount subtract final price from original price
94 - 61.10 = 32.9
Which would be 35% in percent form.
It should be -668 maybe answer B is a typo