Write an explicit formula for the n^th term a n 13, 17, 21, 25, ...

The first term in our arithmetic sequence = 13

The common difference of our arithmetic sequence = 17 - 13 = 4

The formula for finding an equation for any arithmetic sequence is a(n) = A + B(n - 1)

A = the first term

B = the common difference.

Let's plug our numbers in.

a(n) = 13 + 4(n - 1)

Let's check to make sure we're correct.

a(1) = 13 + 4(1 - 1) = 13 + 4(0) = 13 + 0 = 13

a(2) = 13 + 4(2 - 1) = 13 + 4(1) = 13 + 4 = 17

That verifies that our formula is correct.

In conclusion,

a(n) = 13 + 4(n - 1)

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!