Question

Find the indicated sum.

Answer 1

Is it -54?

Answer 2

\[\sum_{k=1}^{4}(-1)^k(k+11)\]
means that you need to find the sum of:
\[(-1)^1(1+11)+(-1)^2(1+11)+(-1)^3(1+11)+(-1)^4(1+11)\]

Answer 3

oops forgot to change the other k

Answer 4

\[(-1)^1(1+11)+(-1)^2(2+11)+(-1)^3(3+11)+(-1)^4(4+11)\]*

Answer 5

i could be wrong but looking at this i don't your number should be so negative big

Answer 6

remember when you have (-1) to some integer your signs will alternate

Answer 7

I originally got 46 but it was incorrect

Answer 8

46 is also to positive big

Answer 9

you do know
(-1)^1=-1
(-1)^2=1
(-1)^3=-1
(-1)^4=1
(-1)^5=-1
(-1)^6=1

the signs alternate

Answer 10

Oh wait I think I see, I'm sorry.
one sec

Answer 11

2?

Answer 12

that seems more reasonable to me

Answer 13

and also correct :)

Answer 14

okay, thank you :3