Combinatorics/Factorial Problem

[kuahji]

I need to prove algebraically

I couldn't get the LaTex to work properly, so I just wrote it up on my computer,

http://img703.imageshack.us/img703/4204/miscj.png

Where am I going wrong here? Is my factorial algebra just incorrect, am I even on the right track?

 

[tiny-tim]

hi kuahji!

(n-1)_k-1 has (n - 1 - (k - 1))! = (n - k)! on the bottom

 

[kuahji]

Thanks :)