Thread: simplify the ratio of factorials

1. simplify the ratio of factorials

(n+1)! / (n-2)!

thx 4 all the ppls that come in and read my post ^^

2. Originally Posted by cwlcwl1212
(n+1)! / (n-2)!
thx 4 all the ppls that come in and read my post ^^
Hint:

3. i understand that (n+1)! = (n+1) x (n+1-1)

but i don't understand how can i extract (n-2)! to the equation i need...

4. n! = n * (n-1) * (n-2)!

5. Originally Posted by cwlcwl1212
i understand that (n+1)! = (n+1) x (n+1-1)
Well, there's your problem, then, because what you "understand" is wrong.
What is true is that (n+1)!= (n+1)(n+1-1)(n+1- 2)... (3)(2)(1)= (n+1)(n)(n-1)(n-2)...(3)(2)(1).

but i don't understand how can i extract (n-2)! to the equation i need...