Can someone please help me get this the correct answer is -6026/13

find the sum of K 12-57

57

E(Sum)7-4k

k=12 13

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- Jul 28th 2008, 10:26 PMhelpless13Help find Sum
Can someone please help me get this the correct answer is -6026/13

find the sum of K 12-57

57

E(Sum)__7-4k__

k=12 13 - Jul 28th 2008, 10:28 PMJhevon
- Jul 28th 2008, 10:31 PMhelpless13Reply
yes that's what i'm trying to write

- Jul 28th 2008, 10:31 PMCaptainBlack
Would that be:

$\displaystyle

\sum_{k=12}^{57} \frac{7-4k}{13}

$

This is an arithmatic progression with first term $\displaystyle -\ \frac{41}{13}$ (which corresponds to $\displaystyle k=12 $), common difference $\displaystyle -\ \frac{4}{13}$ and with $\displaystyle 57-12+1 = 46$ terms. You should have a forumla for this.

RonL - Jul 28th 2008, 10:35 PMhelpless13
I do have the formula I just cant get the write answer i dont know what im doing wrong

- Jul 28th 2008, 10:37 PMhelpless13
I know you have to take the sum of the first 57 terms and subtract the first 12 but i don't get the correct answer

- Jul 28th 2008, 10:42 PMhelpless13Thanks
Alright thanks for your help i got it now