What is the smallest integer that can possibly be the sum of an infinite geometric series whose first term is 9?

The formula for the sum of an infinite series is:  Sum  =  a/(1 - r) provided that -1 < r <  1.

As r gets closer and closer to -1, the sum gets closer and closer to 4.5; so x can be 5 (if r = -4/5).

Thanks Geno, 

I had to think about that one!