Question

Calcule o valor de n sabendo que: a) n!=90/(n-2)!

Answer 1

Resposta:

Se for n!=90*(n-2)!

n*(n-1)*(n-2)! = 90*(n-2)!

n*(n-1) = 90

n²-n-90=0

n'=[1+√(1+360)]/2=(1+19)/2=10

n''=[1-√(1+360)]/2=(1-19)/2<0 , ñ serve

Resposta =10