Please help? summation notation

enter image source here

1 Answer
jonathan n.
May 2, 2018

Look below

Explanation:

choice A states #sum_(k=1)^5 (-3)^k = -3 +9 - 27 +81 - 243#

Choice B states #sum_(k=1)^5 (-3)^(k+1)# which is an obvious nope

Choice C states #sum_(k=1)^5 (-1)^k 3^(k+1) = (-1*9)=-9# which is a nope, which leaves us off with choice D

Related questions
Impact of this question
1039 views around the world
You can reuse this answer
Creative Commons License