A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 4 years ago
What is the sum of the arithmetic sequence 137, 125, 113 …, if there are 38 terms?
anonymous
 4 years ago
What is the sum of the arithmetic sequence 137, 125, 113 …, if there are 38 terms?

This Question is Closed

myininaya
 4 years ago
Best ResponseYou've already chosen the best response.2Do you see that the numbers are increasing by 8?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0i would do it the old school way and keep subtracting 12 until you get 38 terms, then add lol

myininaya
 4 years ago
Best ResponseYou've already chosen the best response.2\[\sum_{i=0}^{37}(137+8i)=137+8(0)+\sum_{i=1}^{37}(137+8i)\] Now use \[\sum_{i=1}^{n}i=\frac{n(n+1)}{2} \text{ and } \sum_{i=1}^{n}c=cn\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Im still not getting the correct answer

Zarkon
 4 years ago
Best ResponseYou've already chosen the best response.0whay are people using d=8

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0i dont know im gonna guess

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Whenever you need to find the sum of an arithmetic series use this formula: \[ \frac n 2 \left( 2a+ (n1) \right)\times d) \tag{1}\] a= first term n= number of terms d= common difference Here, \(n= 38, a = 137 \) and \( d = 12\). Substituting these in \((1)\), and assuming my algebra is right you answer should be \(3230 \)

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0I know but the answer does not show up in the multiple choose

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0@NatalieLove: Revert if you need help in proving that formula.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0We are doing the same steps the test its incorrect. It does not show up as a choose Thank You

myininaya
 4 years ago
Best ResponseYou've already chosen the best response.2omg lol I said increasing by 8 and then continue to think the thingy was increasing by 8 sometimes i wonder about myself lol
Ask your own question
Sign UpFind 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
 Engagement 19 Mad Hatter
 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.