The coefficient of `x^(18)` in the product `(1+x)(1-x)^(10)(1+x+x^(2))^(9)` is

The cofficient of x^(18) in the product (1 + x) (1 - x)^(10) (1 + x + x^(2))^(9) is (A) 84 (B) -126 (C) -84 (D) 126

The coefficient of x^(18) in the expansion (1+x)(1-x)^(10)(1+x+x^(2))^(9) is

The coefficient of x^(15) in the product of (1-x)(1-2x)(1-2^(2)x)(1-2^(3)x)(1-2^(4)x)......(1-2^(15)x)

The coefficient of x^(49) in the product (x - 1)(x-3)… (x-99) is

The coefficient of x^15 in the product (1-x)(1-2x) (1-2^2 x) (1-2^3 x) …. (1-2^15 x) is :

Find the coefficient of x^(18) in the polynomial f(x)=(1+x)^(20)+x(1+x)^(19)+x^(2)(1+x)^(18)+.........+x^(18)(1+x)^(2)

The coefficient of x^9 in the expansion of (1-5x)/(1+x) is

The coefficient of x^9 in the expansion of (1-5x)/(1+x) is