Question

giving a fan and medal!!!!
Write the sum using summation notation, assuming the suggested pattern continues.

-9 - 4 + 1 + 6 + ... + 66

Answer 1

options are attached

Answer 2

it means that u will put n=0,1,2 ....,13,14,15 into -9 +5n one by one and then add them u will get the answer

Answer 3

thnks for replying,but how do u know which option is the correct answer?

Answer 4

yes yur series is correct
but there is no options written .

Answer 5

oops:(sorry!i will post the options in a sec:)

Answer 6

okay :)

Answer 7

I'm pretty sure it's 456

Answer 8

Using the explicit formula for Arithmetic series, we get 66= -9+(n-1)5, and n=16. Once we input that into (16/2)(-9+66), we get 456

Answer 9

@maylaa is it the option there?

Answer 10

465

Answer 11

im sorry @Haseeb96 and @Stella_l

Answer 12

B is the correct answer

Answer 13

thnku sooooooooo much!

Answer 14

Just help three more persons and say to them that help three more persons anywhere

Answer 15

ok:)

Answer 16

:)

Answer 17

@Haseeb96 how did u get n=15?

Answer 18

Because it was written on the summation sign above and i have solved it also but now I am on smart phone

Answer 19

ok,thnx again:)