Anyone wan't to join my zoom?And if no then don't answer and don't just use my for points. Meeting ID: 932 1853 1197

Passcode: 49mYr4

why are so many people doing these

It is the first choice.

Step-by-step explanation:

This is a sequence where

the next term is obtained by adding 6.

first term = -9 + 6(0) = -9

second term = -9 + 6(1) = -3

third term = -9 + 6(2) = 3

4th term = -9 + 6(3)  = 9  

and 81 = -9 + (6*15).

So the answer is  Sigma (-9 + 6n)  from n= 0 to n = 15.