# Homework Help: Find all values of x in which the series converges

1. Mar 25, 2012

### turbokaz

1. The problem statement, all variables and given/known data
Find all values of x for which the series Ʃ (4x+5)^n/2^n converges. (n=0; n→∞)
(3/4,7/4)
(-7/4,7/4)
(-5/4,5/4)
(-7/4,-3/4)

2. Relevant equations

3. The attempt at a solution
I think the answer is -7/4,-3/4. If I remember correctly, there is a test that states that a series converges if the limit goes to 0. Is this correct?

2. Mar 25, 2012

hi turbokaz!