7.4 Properties of Binomial Coefficients (JEE Foundation)

Let $P(x) = (1+x-3x^2)^{2163} = a_0 + a_1x + a_2x^2 + ...$ The sum of coefficients is obtained by putting $x=1$ in the polynomial. Sum = $P(1) = (1 + 1 - 3(1)^2)^{2163} = (2-3)^{2163} = (-1)^{2163} = -1$.