Question

Write the sum using summation notation, assuming the suggested pattern continues.

-4 + 5 + 14 + 23 + ... + 131

Help???;(

Answer 1

by any chance is there a common difference you can espy?

Answer 2

if we add 4 to it all we might be able to see it better

Answer 3

{-4 + 5 + 14 + 23 + ... + 131} + 4

{0 + 9 + 18 + 27 + ... + 135}

Answer 4

\[\sum_{n=0}^{oo}(-4+9)\]

Answer 5

is that correct? @amistre64

Answer 6

9n and the summation is not to infinity .... but your on the right track

Answer 7

-4+9n = 131, solve for n

Answer 8

9n*

Answer 9

i got 15

Answer 10

so instead of infinity it would be 15 right!?

Answer 11

good, then 15 up top instead of infinity

Answer 12

awesome sauce! you're beginning to become my new best friend haha this subject is killing me..

Answer 13

@amistre64

Answer 14

it just takes some practice is all :)