Question

resolva as equações​

Answer 1

a)

n!/(n -2)! = n*(n - 1)*(n - 2)!/(n - 2)! = n^2 - nn

d) (n - 1)!/(n - 3)! = (n - 1)*(n - 2)*(n - 3)!/(n - 3)! = n^2 - 5n + 6