Question

simplifique (n-5)!/(n-4)!

Answer 1

5! = 5.4.3.2.1 certo?!
ou
5! = 5. (5-1) . (5-2) . (5-3) . (5-4) 
5! = 5. (5-1) . (5-2)! 


(n-4)! = (n-4) . (n-5)! 

(n-5)!  /  [(n-4) . (n-5)! ] = n-4