Question

me ajudem por favor
calcule
a) n!/(n-1)!
b) n!/(n-2)!
c (n-1)!/(n-2)!​

Answer 1

Explicação passo-a-passo:

a)

$\sf \dfrac{n!}{(n-1)!}=\dfrac{n\cdot(n-1)!}{(n-1)!}$

$\sf \red{\dfrac{n!}{(n-1)!}=n}$

b)

$\sf \dfrac{n!}{(n-2)!}=\dfrac{n\cdot(n-1)\cdot(n-2)!}{(n-2)!}$

$\sf \dfrac{n!}{(n-2)!}=n\cdot(n-1)$

$\sf \red{\dfrac{n!}{(n-2)!}=n^2-n}$

c)

$\sf \dfrac{(n-1)!}{(n-2)!}=\dfrac{(n-1)\cdot(n-2)!}{(n-2)!}$

$\sf \red{\dfrac{(n-1)!}{(n-2)!}=n-1}$