Question

Write an equation for the nth term of the given geometric sequence 4,20,100,...,an
a.100(5)^n-1
b.4(1/5)^n-1
c.4(5)^n-1
d.4(1/5)^n+1
HELP PLEASE =)

Answer 1

to find the nth term of a geometric series..........
\[a_n=a_1 \times r^{n-1}\]

Answer 2

a(n) is the nth term
a(1) is the first term of the sequence
r is the common ratio