SOLUTION: Determine a rule for the nth term of the sequence. Then find a17. 86, 82, 78, 74, 70 ... a17 =?

Algebra ->  Square-cubic-other-roots -> SOLUTION: Determine a rule for the nth term of the sequence. Then find a17. 86, 82, 78, 74, 70 ... a17 =?      Log On


   

Question 387983: Determine a rule for the nth term of the sequence. Then find a17.
86, 82, 78, 74, 70 ... a17 =?
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
an = a1 + (n-1)d = 86 + (n-1)(-4) = 86 - 4n + 4 = 90 - 4n. Hence an = 90 - 4n.
Then a17 = 90 - 4*17 = 22.