## anonymous one year ago Please help!! Write the sum using summation notation, assuming the suggested pattern continues. -9 - 4 + 1 + 6 + ... + 66

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1. anonymous

so you start at -9 and roll to 66 at steps of 5

2. anonymous

Ok. So would the answer be: summation of the quantity negative nine plus five n from n equals zero to infinity

3. anonymous

$\sum_{n=-9}^{\infty}$

4. anonymous

all my answer choices have n=0, then infinity or 15 at the top, and on the side: -45n or (-9+5n). So I thought I would have: infinity at the top, n=0 at the bottom, and (-9+5n) on the side.

5. anonymous

$\sum_{k=0}^{\infty} = -9+(k-1)5$

6. anonymous

change the k to n

7. anonymous

wait... that would mean n=0 is -14

8. anonymous

$\sum_{n=0}^{\infty} = -4+(n-1)5$

9. anonymous

10. anonymous

that way n=0 is -9

11. anonymous

what choice do you have?

12. anonymous

a. summation of negative forty five times n from n equals zero to fifteen b. summation of the quantity negative nine plus five n from n equals zero to fifteen c. summation of the quantity negative nine plus five n from n equals zero to infinity d. summation of negative forty five times n from n equals zero to infinity

13. anonymous

looks like c if you want -9 to infinity

14. anonymous

That's what I thought.

15. anonymous

it works too

16. anonymous

just tested it

17. anonymous

That wasn't correct. Could it be b?

18. anonymous

yea 0 to 15 gives to -9 to 66

19. anonymous

b* dayum i soo sleepy i saw 0 as b