Question

Find S15 for the series -1 + -3 + -5 + -7 +...Type the numeric answer only.

Answer 1

will give medal!

Answer 2

-1-3-5-7-9-11-13-15-17-19-21-23-25-27-29-31=S15

Answer 3

thanks!

Find the 6th term of the sequence in which t1 = -5 and tn = -5tn-1?

Answer 4

please help!!!

Answer 5

n=6
\[t_{1}=-5\]
\[t_{n}=-5t_{n}-1\]
Is this correct?

Answer 6

im not sure??? i dont know how to do this

Answer 7

no, they give the recurrsion, not the explicit

Answer 8

\[t_{n}=-5t_{n-1}\]

Answer 9

Ok, that makes much more sense. I wish that people would use proper format.

Answer 10

it would help yes :)

Answer 11

Ok, so we are given
\[t_{1}=5\]
\[t_{2}=-5\times t_{1}\]

Answer 12

okay....

Answer 13

so -5 times 5?

Answer 14

Right! And that is....?

Answer 15

-25

Answer 16

Correct, so
\[t_{2}=-25\]
\[t_{3}=-5\times t_{2}\]
\[t_{4}=-5\times t_{3}\]
\[t_{5}=-5\times t_{4}\]
\[t_{6}=-5\times t_{5}\]

Answer 17

so the ansswer would be -15,625?

Answer 18

That is the answer that I arrived to!

Answer 19

okay are you willing to help me get started on one more? (:

Answer 20

Sure, post up a new question so that others will be more likely to see it!

Answer 21

okay!