Question

matéria : fatorial , alguem me ajuda ?

Answer 1

a)
$\frac{(n-1)!}{(n+1)!}=\frac{(n-1)!}{(n+1)n(n-1)!}=\frac{1}{n(n+1)}=\frac{1}{n^2+n}$

b)
$\frac{(n-1)!}{(n-3)!}=\frac{(n-1)(n-2)(n-3)!}{(n-3)!}=(n-1)(n-2)=n^2-3n+2$

c)
$\frac{(n+2)!}{(n+1)!}=\frac{(n+2)(n+1)!}{(n+1)!}=n+2$

Answer 2

Oie, Td Bom?!

a)

= [(n - 1)!]/[(n + 1)!]

= [(n - 1)!]/[(n + 1) . n . (n - 1)!]

= 1/[(n + 1) . n]

= 1/[n² + n]

b)

= [(n - 1)!]/[(n - 3)!]

= [(n - 1) . (n - 2) . (n - 3)!]/[(n - 3)!]

= (n - 1) . (n - 2)

= n² - 2n - n + 2

= n² - 3n + 2

c)

= [(n + 2)!]/[(n + 1)!]

= [(n + 2) . (n + 1)!]/[(n + 1)!]

= n + 2

Att. Makaveli1996