Can someone please help with this ?

    -9n+20

This is the same as 20-9n

================================================

Explanation:

The jump from 11 to 2 is "minus 9"

The jump from 2 to -7 is also "minus 9".

Assuming this pattern continues on, we have an arithmetic sequence with

The nth term can be found like so

Let's check the answer by trying n = 3

This shows the third term is -7, which matches what the original sequence shows. The answer is partially confirmed. I'll let you check the other values of n. You should get 11 when trying n = 1, and you should get 2 when trying n = 2.

how am i supposed to answer

step-by-step explanation:

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for