SOLUTION: What is the expression for the nth term for 5,3,-1,-7,-15,-25,-37? I know it goes by -2, -4, -6, -8...but I dont know how to find the expression for an= thanks

Algebra ->  Test  -> Lessons -> SOLUTION: What is the expression for the nth term for 5,3,-1,-7,-15,-25,-37? I know it goes by -2, -4, -6, -8...but I dont know how to find the expression for an= thanks      Log On


   

Question 757787: What is the expression for the nth term for
5,3,-1,-7,-15,-25,-37?
I know it goes by -2, -4, -6, -8...but I dont know how to find the expression for an=
thanks
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!
First term starts at 5, then each new term DECREASES by increasing increments of 2.

5, 5-2, 5-2%2A2, 5-2%2A3, 5-2%2A4,...

Just generalize what you find. You may form the first and second term like this:
5-2=5-2%2A%282-1%29, and 5=5-2%2A%281-1%29;
Any term of the sequence, using n for the index of term, is 5-2%28n-1%29.