OpenStudy (anonymous):

Write the series in summation notation: -3 + 6 - 9 + 12 - 15

5 years ago
OpenStudy (anonymous):

$\sum_{k=1}^{5} (-1)^{k}(3k)$

5 years ago
OpenStudy (anonymous):

$\sum_{k=0}^{4} (-1)^{k}-1(3k)$

5 years ago
OpenStudy (amistre64):

the first one seems adequate to me

5 years ago
OpenStudy (amistre64):

alternating multiples of 3

5 years ago
OpenStudy (anonymous):

do you wanna see the other two answer choices?

5 years ago
OpenStudy (amistre64):

how many correct options can you choose?

5 years ago
OpenStudy (anonymous):

just one

5 years ago
OpenStudy (amistre64):

then since the first one is adequate (i dont know how your author defines proper notation); then the others would seem a bit futile

5 years ago
OpenStudy (anonymous):

well the other two are quite like the first two :P

5 years ago
OpenStudy (amistre64):

if you want to type them up for comparison, that would be fine.

5 years ago
OpenStudy (anonymous):

$\sum_{K=0}^{4}(-1)^{k}(3k)$

5 years ago
OpenStudy (anonymous):

$\sum_{k=1}^{5} (-1)^{k} -1(3k)$

5 years ago
OpenStudy (anonymous):

there :)

5 years ago
OpenStudy (amistre64):

is 3(4) equal to 15?

5 years ago
OpenStudy (anonymous):

no?

5 years ago
OpenStudy (amistre64):

the last 3 simply dont match the numbers in the sequence ....

5 years ago
OpenStudy (anonymous):

so you plug the sequence numbers in for k?

5 years ago
OpenStudy (amistre64):

yes

5 years ago
OpenStudy (anonymous):

oh alright!! thankyou very much :)

5 years ago
OpenStudy (amistre64):

good luck

5 years ago