SOLUTION: So I have the sequence of numbers that goes 13,3,-7,-17... and keeps going. I need to write an equation, but I can't figure out what it could be. Please help?

Algebra ->  Sequences-and-series -> SOLUTION: So I have the sequence of numbers that goes 13,3,-7,-17... and keeps going. I need to write an equation, but I can't figure out what it could be. Please help?      Log On


   

Question 775113: So I have the sequence of numbers that goes 13,3,-7,-17... and keeps going. I need to write an equation, but I can't figure out what it could be. Please help?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
You're subtracting 10 from each term. So this is an arithmetic sequence

First term: 13
Common Difference: -10


an = a1 + d(n-1)

an = 13 + (-10)(n-1)

an = 13 - 10n + 10

an = -10n + 23

The equation for the nth term is