Sum and Product of Coefficients in Binomial Expansion

For a binomial expansion of $(ax + by)^n$, the sum of the coefficients can be found by setting $x=1$ and $y=1$. This simplifies the expression to $(a+b)^n$.

For example, the sum of the coefficients of $(x+y)^6$ is $(1+1)^6 = 64$. If the expression is $(x-y)^n$, the sum of the coefficients is always 0.

The product of the coefficients doesn't have a simple formula and requires knowing the coefficients from Pascal's triangle.