Question

(algebra 1) arithmetic sequences
question in the replies

Answer 1

Do you know the arithmetic sequence formula?

Answer 2

a + (n – 1)^t

Answer 3

Well, close, it's actually:

\(\large a_n = a_1 +(n-1)*d \)

Where \(a_1\) is the first term and d is the difference between the terms.

They already have you \(a_1 \) which is \(a_1 = -7\)
To find d, just the find the difference between each term: -13 - (-10) = -3
-10 -(-7) = -3
-16 -(-13) = -3 and so on..

so we get d = -3

Just plug those into the formula:

\(\large a_n = (-7) +(n-1)(-3) \)

\(\large a_n = -7 +(-3n+3 ) \)

Giving you:

\(\large a_n = -3n -4 \) as your formula.

Answer 4

thank you for the explanation luigi - its been weeks since I've done this so this really helped :]