Two terms in a geometric sequence are a_(5)=15 and a_(6)=1. What is the recursive rule that describes the sequence? SOME ONE PLEASE HELP ME!

Question

(A) a_(1)=50,625; a_(n)=a_(n−1)⋅1/5

(B)a_(1)=759,375; a_(n)=a_(n−1)⋅1/15

(C)a_(1)=11,390,625; a_(n)=a_(n−1)⋅15

(D)a_(1)=225; a_(n)=a_(n−1)⋅5

 

Answer 1

a₆ = a₅(r)

1 = 15(5)

1 / 15 = r

a₅ = a₁(1/15)⁴

15 = a₁(1/50625)

759375 = a₁