Question

if the first term of a gp be 5 and common ragio -5 then find which term is 3125.

Answer 1

A=5
R=-5
Ar*(n-1)=3125
5(-5)*(n-1)=3125
(-5)*(n-1)=625
(-5)*(n-1)=(-5)*4
When bases are equal powers are also equal
(n-1)=4
n=4+1
n=5