Question

algebra 2 help! :)

Answer 1

Do you know how to write the formula for any term in the sequence?

Answer 2

no

Answer 3

Well, that's pretty essential knowledge!

\[a_n = a_1r^{n-1}\]

Answer 4

i was checking my notes and i wrote this (attachement below)...

Answer 5

Yes, that's also essential to know, but not for this problem. That's the sum of the first \(n\) terms. We just want to find the \(n\)th term in this problem, right?

Answer 6

oh ok... how do i use the formula you showed me

Answer 7

you want to find the 9th term, which is \(a_9\)

\[a_n = a_1 r^{n-1}\]\[n = 9\]\[r = -\frac{1}{3}\]\[a_1 = -7\]
Plug in the numbers and turn the crank...

Answer 8

a_9 = -7(-1/3)^(9-1)= -7/6561 <--?

Answer 9

That's correct!

Answer 10

omg! it wasnt hard after all :P thank you so much! :D