Find the coefficient of `x^4` in the expansion of `(1+x+x^2+x^3)^(11)dot`

Find the coefficient of x^4 in the expansion of (1+x+x^2+x^3)^6

Find the coefficients of x^4 in the expansion of (1+x+x^2)^3

Find the coefficient of x^4 in the expansion of (1+x+x^2 +x^3 )^11 x^4 in the expansion of (2-x+ 3 x^2)^6

Find the coefficient of x^(7) in the expansion of (1+3x-2x^(3))^(10)

Find the coefficient of x^7 in the expansion of (3x^2+ 1/(5x))^11

Find the coefficient of x^(4) in the expansion of (2-x+3x^(2))^(6)