Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

NatalieLove

  • 2 years ago

What is the sum of an 8–term geometric series if the first term is 12 and the last term is –3,359,232?

  • This Question is Closed
  1. Matt6288
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    What is the sum of an 8–term geometric series if the first term is 12 and the last term is –3,359,232 nth term = a r ^ ( n - 1 ) 8th term = 12 r ^ ( 8 - 1 ) = –3,359,232 12 r ^ ( 7 ) = –3,359,232 r^7 = -279,936 r = – 6

  2. NatalieLove
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its not giving me answer when i plug it in

  3. Matt6288
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    n Σ a r^k = a ( 1 - r^(n+1)) / ( 1 - r ) k=0 7 Σ 12 r^k = 12 ( 1 - ( – 6 ) ^(7+1)) / ( 1 - ( – 6 )) k=0 ...............= 12 ( 1 - ( – 6 ) ^(8)) / 7 ...............= 12 ( 1 - ( 1,679,616 )) / 7 ...............= 12 ( –1,679,615 ) / 7 ...............= –20,155,380 / 7 ...............= –2,879,340

  4. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.