Question

PLEASE HELPPP

what is the sum of the finite arithmetic series? (-15) + 0 + 15 + 30 + ... + 195

Answer 1

do you want me to throw a calculator at you?

Answer 2

lol I don't know how to do it

Answer 3

can u tell me how?? @sourwing

Answer 4

This might help
http://www.regentsprep.org/Regents/math/algtrig/ATP2/ArithSeq.htm

Answer 5

I'M POOPING!

Answer 6

@nikato thank you! but how do I fin the sum?
@sourwing lol have fun

Answer 7

btw I know it says how there , im looking at it

Answer 8

You should use An= a1 + (n-1)d to find which nth term 195 is.

Plug in An=195
a1= the first term which is -15
And d=common difference which is15

And now you want to find n

Answer 9

okay I got 1355

Answer 10

ok, I'm done pooping. Do you still need help?

Answer 11

I got a different answer.
We're you able to solve for n with what I told you

Answer 12

Well if you did it correctly.

195=-15+ (n-1)15
195=-15+15n-15
Combine like terms
195=-30+15n
225=15n
n= 15

Answer 13

Plug this into the second equation

n(a1+An)
-----------
2

15(-15+195)
------------- = ?
2

Answer 14

okay now I got 3000

Answer 15

@sourwing lol yes!!

Answer 16

nope I got 1350! I think its right .. thaaaank you! :D

Answer 17

looks like you got it