Pls asap i’d appreciate it, i have no idea how to do this

The correct answer is D.

The symbol you are looking at is sigma, which means sum of all. Because the number on the bottom is 1 and the top is 6, these are the start and end numbers for our n value. Therefore, it means to add together all of the values of your expression (n -3), for all of the values with n equaling between 1 and 6. So let's plug in all of the numbers for n they ask for and see what we have.

1

1 - 3 = -2

2

2 - 3 = -1

3

3 - 3 = 0

4

4 - 3 = 1

5

5 - 3 = 2

6

6 - 3 = 3

Now, when we add all of these numbers up, we look for the answer.

-2 + -1 + 0 + 1 + 2 + 3 = 3

This is the answer we see in D