Question

Find the indicated sum.


A. 2
B. 54
C. 46
D. -54
I got B

Answer 1

express the four terms

(-1)(1+11) = -12
(1)(2+11) = 13
(-1)(3+11) = -14
(1)(4+11) = 15

now, add the numbers up

Answer 2

I got 2, so its A?

Answer 3

yes.
did you understand how I expanded the terms?

Answer 4

from k = 1 to k = 4

Answer 5

I think so.(: Thank you very much

Answer 6

yw.

Answer 7

you got the numbers right but you missed the \((-1)^k\) part that gives them the signs!

Answer 8

I got others. If you want to check them too. Im on a course that I have to teach myself. :/
I just like this class to graduate. so I want to make a super good grade

Answer 9

Oh man what was I thinking!!! Glad you caught that

Answer 10

post them as questions like this. There are many good people here to help you.

Enjoy your time on Open Study