Find the coefficient of `x^k` in `1 +(1 +x) +(1 +x)^2+.. +(1+x)^n (0 <=k<=n)`.

Find the coefficient of x^k in1+(1+x)+(1+x)^2++(1+x)^n(0lt=klt=n)dot

Find the coefficient of x^k in1+(1+x)+(1+x)^2++(1+x)^n(0lt=klt=n)dot

Find the Coefficient of x^(n) in ((1+x)/(1-x))^(2)

Find the coefficient of x^r in the expansion of 1 +(1 + x) + (1 + x)^2 +.......+ (1 + x)^n .

The coefficient of x^(n) in (1)/((1-2x)(1-3x)) is

Find the coefficient of x^(n) in the expansion of (1+x)(1+x)^(n).

Find the coefficient of x^n in the expansion of (1+x)(1+x)^ndot

Statement-1 Coefficient of x^49 in (1+ x)(3 +x)(5 +x)......... (99+x) is 2500 and Statement. 2 The coefficient of x^k in (1 +x)l (2 +x)m (3 +x)n where l +m +n -k= 1 is (l+ 2m +3n).