Posted by **Laura** on Saturday, June 16, 2007 at 8:17am.

Find the sum of 20 (summation notation symbol)k=1 then (3k-5)

If you mean the sum of the first 20 terms, beginning with k=1, of

ak = 3k - 5,

that would be -20 x 5 = -100

PLUS the sum of the first 20 terms of

ak = 3k

The latter is 3 times the sum of

1+2+3+...20 ,

or 3*(20)(21)/2= 630

So the answer is 630 - 100 = 530

## Answer This Question

## Related Questions

- Calculus 2 - I need help in solving an initial-value problem and a few series ...
- Precalculus - Find the sum of the first 50 terms of the sequence 2,4,6,8...
- arithmetic - 1. The first and last term of an A.P are, a and l respectively, ...
- Precalculus - 1.) Use sigma notation to describe the sum of the first ten terms ...
- arithmetic - 1. The first and last term of an A.P are, a and l respectively, ...
- Math3c - 1.Find an A.P. such that the sum of the first three terms is one half ...
- Further mathematics - An exponential sequence (GP)of positive terms and a linear...
- math - Hi. I'm having trouble with the summation of n from i=2 of ((2^n-i)(2^n...
- Algebra - Express the sum below using summation notation. Use 1 as the lower ...
- Calculus - The problem I have is a summation from 1 to infinity for (-1)^n/n. I ...

More Related Questions