Write a Formula for the General Term (The Nth Term) $$- 5 , - 10 , - 20 , - 40 , - 80 , \ldots$$

Multiple Choice

Write a formula for the general term (the nth term) of the geometric sequence.
- $$- 5 , - 10 , - 20 , - 40 , - 80 , \ldots$$

A) $a _ { n } = - 5 ( 2 ) ^ { n - 1 }$
B) $a _ { n } = - 5 ( 2 ) ^ { n }$
C) $a _ { n } = a _ { 1 } + 2 ^ { n }$
D) $a _ { n } = - 5 ( 2 n )$