Thread: binomial coefficients/Pascal triangle shortcut with a negative?

I am learning how to expand binomial coefficients using Pascal's Triangle.
All the examples I see are when 'a' and 'b' are positive. What is the trick in terms of signs when either 'a' or 'b' is negative?

Originally Posted by delgeezee

I am learning how to expand binomial coefficients using Pascal's Triangle.
All the examples I see are when 'a' and 'b' are positive. What is the trick in terms of signs when either 'a' or 'b' is negative?

Here is an example.
.

Originally Posted by Plato

Here is an example.
.

Thanks, that makes sense!