Factorial simplification problem

[NewtonianAlch]

Homework Statement

In my calculus book they have the following simplification:

$\frac{k!}{(k+1)!}$ = $\frac{1}{k+1}$

I do not quite understand how that's occurred.

 

[PAllen]

Have you tried simply writing out the numerator and denominator from the factorial definition?

 

[NewtonianAlch]

Doh!