Answer:
Step-by-step explanation:
the least common denominator would be 4/10 and 2/10 but that isn’t an option. none of the answers provided are correct. there’s a mistake in the answers.
Answer:
4 and -4, both points are four away from zero and absolute value does not care about whether the number is positive or negative
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.