What is a nth term 15 9 3 -3 -9?

Answer 1

In order to find the nth term, you need to see the difference between the numbers first, so you can see that here, the numbers keep getting smaller by 6. Therefore, the equation must be the term = something (x) -6n. To find that x, you have to look at any of the numbers, for example, 15. You know that n=1 in this case because it is the first number so

15 = x - (6*1)

15 = x - 6

(now add 6 to both sides)

21 = x

So you now know that the nth term = 21 - 6n