Question

Write the explicit formula for the geometric sequence. Then find the fifth term in the sequence.

Answer 1

Answer:

B. an = -4 *(-2)^n-1;-64

Answer 2

The sequence:  a 1 = - 4,  a 2 = 8,  a 3 = -16,...
a 2 = a 1 * r
8 = - 4 * r
r = 8 : ( - 4 ) 
r = - 2
a n = a 1 * r^(n-1)
a 5 = - 4 * ( - 2 ) ^4 = - 4 * 16 = - 64
Answer:
The fifth term in the sequence is - 64.