This is my first post and I do not know how to write in the tags that make the math code look all pretty so if someone could link me to a place that could teach me that would also be nice
My question is how to simplify the following
SUMMATION from (k = n) to (n + r) of(C(k, k-n)).
that is sigma with k=n on bottom and n+r on top
thanks in advance
