SOLUTION: 18. https://answers.yahoo.com/question/index?qid=20210419170616AA87mlx

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: 18. https://answers.yahoo.com/question/index?qid=20210419170616AA87mlx      Log On


   

Question 1179199: 18.
https://answers.yahoo.com/question/index?qid=20210419170616AA87mlx
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
nth term of the an arithmetic sequence is:
a%5Bn%5D=a%5B1%5D%2Bd%28n-1%29
given:
a%5B1%5D=49
a%5B8%5D=14
a%5Bn%5D=49%2Bd%28n-1%29...........use a%5B8%5D=14 to calculate d
14=49%2Bd%288-1%29
14=49%2B7d
14-49=7d
7d=-35
d=-5
your formula is:
a%5Bn%5D=49-5%28n-1%29
find
a%5B27%5D
a%5B27%5D=49-5%2827-1%29
a%5B27%5D=49-5%2826%29
a%5B27%5D=49-130
a%5B27%5D=-81