Question
Let $\alpha, \beta, \gamma$ be the three roots of the equation $x^{3}+b x+c=0$. If $\beta \gamma=1=-\alpha$, then $b^{3}+2 c^{3}-3 \alpha^{3}-6 \beta^{3}-8 \gamma^{3}$ is equal to :
Let $\alpha, \beta, \gamma$ be the three roots of the equation $x^{3}+b x+c=0$. If $\beta \gamma=1=-\alpha$, then $b^{3}+2 c^{3}-3 \alpha^{3}-6 \beta^{3}-8 \gamma^{3}$ is equal to :