Use a Combinatorial Argument to evaluate the product of

[lladams]

Give a combinatorial argument to evaluate the sum of k=0 to n of C(n,k) times C(m,k) (the previous should be in sigma notation), where n ≤ m[/img]

 

[pka]

Sorry, but your post is unreadable!
Please try again. There is nothing to prove there.

 

[lladams]

lladams

Sorry about that, here it is again:

Give a combinatorial argument to evaluate the sum of k=0 to n of C(n,k) times C(m,k) (the previous should be in sigma notation), where n is less than m