Question

Find an explicit formula for the sequence 30\,,\,150\,,\,750\,,\,3750,...30,150,750,3750,...30, space, comma, space, 150, space, comma, space, 750, space, comma, space, 3750, comma, point, point, point.

Answer 1

The series shown is an geometric series and the explicit formula is given by:
an=ar^(n-1)
where
a=first term
n=number of terms
r=common ratio
from the sequence:
a=30
r=5
thus the explicit formula will be:
an=30(5)^(n-1)
hence the answer is:
an=30(5)^(n-1)