# Math Help - Positive integer n question help please

1. ## Positive integer n question help please

prove that.

where nCk = combintions.....

2. $\sum_{k=0}^{n} nC_k*k^{(n-k)} * (n-k)^k$ $\leq \frac{1}{2} *n^n$

prove that.

where $nC_k =$ combinations.....

Just trying my latex skills out, but is that what you mean? This may help others out if it is right.