1. The problem statement, all variables and given/known data This isn't a specific problem rather I don't know how to reduce factorials and this is giving me a hard time when I try the ratio test. For an example I'll use (2n+1)!/(2n+3)! 2. Relevant equations 3. The attempt at a solution I attempt it by writing out some solutions in this case for n=0 to n=3 or so. I start of writing it as (1*3*5*7)/(3*5*7*9) so it reduces down to 1/9 when n=3 so the incorrect reduced equation is 1/(2n+3). How should I approach problems like these?