Question

Calcule fatorial:

a) 7! . 9! / 8! . 5!

b) (n+4)! / (n+2)!

c) (n - 5)! / (n - 3)!

Answer 1

a) 7! . 9! / 8! . 5! = 7.6.5! . 9.8! / 8! . 5! = 7.6.9 = 378

b)(n+4)! / (n+2)! = (n+4)(n+3)(n+2)! / (n+2)! = (n+4)(n+3) = n²+7n+12

c) (n-5)! / (n-3)! = (n-5)! / (n-3)(n-4)(n-5)! = 1 / (n-3)(n-4) = 1 / (n²-7n+12)