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) in 1+(1+x)+(1+x)^(2)+...+(1+x)^(n)(0<=k<=n)

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

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

What is the coefficient of x^(n) in (x^(2) + 2x)^(n-1) ?

Find the coefficient of x^(4) in the expansion of (1+x)^(n)*(1-x)^(n)

The coefficient of x^(2) in (1+x)(1+2x)(1+4x)...(1+2^(n)x)

Find the coefficient of x^(n) in (1+(x)/(1!)+(x^(2))/(2!)+...+(x^(n))/(n!))^(2)

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).