The answer is 1.
Thank you for waiting!
<em>x = - 2.5</em>
- <em>Step-by-step explanation:</em>
<em>Hi there !</em>
<em>4 - (2x + 4) = 5</em>
<em>4 - 2x - 4 = 5</em>
<em>- 2x = 5</em>
<em>2x = - 5</em>
<em>x = - 5 : 2</em>
<em>x = - 2.5</em>
<em>Good luck !</em>
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.