SubArea: CombinatoricsLevel: BProject ID: 9000140501Accepted: 1Clonable: 0Easy: 1Simplify for \(n\in \mathbb{N}\). \[ \frac{n!} {(n - 1)!} \]\(n\)\(\frac{n} {n-1}\)\(\frac{n!} {n!-1!}\)\(- 1\)
