Hello! Thanks for taking the time to look at my post. I am studying sequences and series and I don't understand the part about factorials. An example problem is below:
My goal for both of the above is to simplify the ratio of factorials. I know that a factorial is the product of all the numbers (i.e. 6! is 1*2*3*4*5*6= 720) but I can't grasp how that works when the n's get thrown in there. Any help would be greatly appreciated!