Question

Resolvam essa equação ​

Answer 1

Vamos là.

a)

A(n, 2) = 30

n!/(n - 2)! = 30

n*(n - 1) = 30

n² - n - 30 = 0

(n - 6)*(n + 5) = 0

n = 6

b)

A(n,4)/A(n,3) = 8

(n - 3)!/(n - 4)! = 8

(n - 3)! = 8*(n - 4)!

(n - 3)*(n - 4)! = 8*(n - 4)!

n - 3 = 8

n = 11