Any help would be really appreciated!! Help with this geometric sequence?

Question

Any help would be really appreciated!! Help  with this geometric sequence?

anonymous · Answer

attachment

anonymous · Answer

@agent0smith

agent0smith · Answer

Find the first term a1 and the common ratio r, then http://www.regentsprep.org/Regents/math/algtrig/ATP2/ArithG11.gif

anonymous · Answer

Okay thank you! Working on it right now

anonymous · Answer

common ratio is dividing by 4

anonymous · Answer

I think the first term is 256...

agent0smith · Answer

so r is 1/4, that leaves 2 choices

they give you weird formulas.. just plug in a few n's, like 1, 2,3 into each formula, check which gives 256, 16, 4

anonymous · Answer

Okay, thanks!

agent0smith · Answer

Actuallty just check n=1, 2, 3 for all options to be safe

anonymous · Answer

Alright, I'm checking those : )

anonymous · Answer

I think the answer is D. Is that correct?

agent0smith · Answer

D won't give 256 as a first term.

agent0smith · Answer

Only one will give 256 when n=1

anonymous · Answer

Oops sorry!

anonymous · Answer

The answer is C than!

agent0smith · Answer

Use a calculator to check

agent0smith · Answer

Or show me what you're doing, because you're not using exponents correctly it seems.

anonymous · Answer

I did 4^1-5=4^4
Then I multiplied it 4*4*4*4=256

agent0smith · Answer

1-5  = ?

it's not equal to positive 4 :P

anonymous · Answer

What a dumb mistake :0 sorry!

agent0smith · Answer

:) it's okay. I'm sure you can find the correct answer now.

anonymous · Answer

Yep for sure! =)

anonymous · Answer

Okay I got B now is that right? @agent0smith

agent0smith · Answer

Yes

anonymous · Answer

Great! : ) Thank you so much for all the help and sorry about all the mistakes!

anonymous · Answer

@agent0smith Thanks for the medal! =)

agent0smith · Answer

Welcome :)