In my textbook there is the following binomial expression which is solved to a numerical answer:
I'd like to know if there is a way to calculate this result without having to calculate the entire summation.
I know that from the binomial theorem:
But how can I use this to calculate the value above? Because the lower bound of the sum in the textbook example is not 0, I cannot us the binomial theorem straight away. Is there some way in which I can rewrite the formula to make use of the binomial theory?