Question

how would you expand the series and evaluate:

equation below ...

Answer 1

\[\sum_{k=1}^{5} -5 (2)^{k} -1\]

Answer 2

a) -5 - 10 - 20 - 40 - 80 = -90
b) -5 - 10 - 15 - 30 - 40 = -155
c) -5 - 10 - 20 - 40 - 80 = -155
d) -5 - 10 - 15 - 30 - 40 = -90

Answer 3

repeat the rule 5 times, using k=1,2,3,4,5 in succession

-5(2)^1 - 1
-5(2)^2 - 1
-5(2)^3 - 1
-5(2)^4 - 1
-5(2)^5 - 1

and add the results

Answer 4

your options dont match up with what youve presented

Answer 5

you need to put your exponent all in {..} brackets

Answer 6

\[\sum_{k=1}^{5} -5 (2)^{k-1}\]

Answer 7

-5(2)^0
-5(2)^1
-5(2)^2
-5(2)^3
-5(2)^4

Answer 8

options A and D simply dont add up to begin with, so it narrows down to B or C

Answer 9

i see where i went wrong. thanks for helping me see it. and the answer is c) -5 - 10 - 20 - 40 - 80 = -155

Answer 10

C is correct, yes

Answer 11

thanks so much !

Answer 12

youre welcome