What is the explicit rule for this geometric sequence? a1=−15;an=15⋅an−1

an=−15⋅15n−1

an=−15(15)n−1

an=15(−15)n−1

an=15⋅(−15)n−1

I'm not sure if I'm 100% correct but I think it is C

Step-by-step explanation:

an=1/5⋅(−15)n−1

Step-by-step explanation:

I think the problem is a1=−15;an=1/5⋅an−1 and not a1=−15;an=15⋅an−1

I took the test :)