Question

Simplifique as expressões: a) n! -(n+1)!/n!
b) (n+2)!/(n-1)!

Answer 1

a) nfatorial - (n+1.nfatorial)/ nfatorial
= -n^2 + 1

b) (n+2).(n+1).(n).(n-1fatorial)/ (n-1fatorial) (cancela os fatoriais)
(n+2)(n+1)(n)
(n^2+3n+2)(n)=

n^3+3n^2+ 2n