7.Find the coefficient of `x^0` in `x^2+3x+2 =0`.

Find the coefficient of x^(5) in (1+2x+3x^(2).........

Find the coefficient of x^(5) in the expansion of ((2 + 3x + 4x^(2)))/(e^(x))

Find the coefficient of x^(4) in the expansion of (3x^(2)+2x)/((x^(2)+2)(x-3)) specifying the region which the expansion is valid.

Find the coefficient of x^3 in the expansion of (1+x+2x^2)(2x^2-frac{1}{3x})^9

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

Find the coefficient of x^(10) in the binomial expansion of (2x^(2)-(3)/(x))^(11), when x!=0

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