Let α, β, γ be the three roots of the equation x3+bx+c=0. If βγ =1=-α, then b3+2c3-3α3-6β3-8γ3 is equal to
Let SK = \(\frac{1+2+...+ K}{K}\) and \(\displaystyle\sum_{j=1}^{n}S_j^2=\frac{n}{A}(Bn^2+Cn+D)\), where A,B,C,D∈N and A has least value. Then