Question

Simplifique as expressões
a)An-1,n-3/An+1,n

Answer 1

Boa tarde

Tem que utilizarformula , dada por:

A(n,p) = n!/(n-p)! 

A(n-1,n-3) = (n-1)!/2!

A(n+1,n) = (n+1)!/1!

((n-1)!/2!) / ( (n+1)!/1! ) = 

((n-1)!/2) * (1/(n+1)!) = (n - 1)!/(2*(n+1)*n*(n-1)!) =

1/(2n² + 2n)