n+1 A 6. (4 points) Give a combinatorial proof of the identity [(k-1)(n+2-k) = (n + 2)! 3 k=2 (Hint: Let A be a set with
Posted: Thu May 05, 2022 6:36 pm
n+1 A 6. (4 points) Give a combinatorial proof of the identity [(k-1)(n+2-k) = (n + 2)! 3 k=2 (Hint: Let A be a set with n+2 elements laid out in a line. When creating a subset with 3 elements, start by choosing the "middle" element and consider varying the position of the middle element! It may help to draw out an example. ) Gi +7