Question

Write the sum using summation notation, assuming the suggested pattern continues.

-3 + 6 + 15 + 24 + ... + 132

Answer 1

Summation(9n - 12)

n ranges from 1 till infinity

Explanation:

General form of the sequence:

It is an Arithmetic sequence with:

first term: -3

common difference: 6 - -3 = 9

Nth term: -3 + (n - 1)(9)

-3 -9 + 9n

9n - 12

Summation(9n - 12)

n ranges from 1 till infinity

Answer 2

Explanation:

Step 1: Find a notation

If you look at the pattern, you will see that to get the next number. You need to add 9 to it. Therefore the pattern will look like this:

`x_n_+_1=x_n+9`

Answer:
`x_n_+_1=x_n+9`