permütasyon

Question

9. P(n+1 , 2) = P ( n+1 , 3) 

  n=?

Answer 1

İpucu:

$$9\cdot\frac{(n+1)!}{(n+1-2)!}=\frac{(n+1)!}{(n+1-3)!}\Rightarrow n=?$$