If the sum of two roots of $x^3+p x^2+q x-5=0$ is equal to its third root, then $p\left(p^2-4 q\right)=$

$$ 4+\frac{1}{4+\frac{1}{4+\frac{1}{4+\ldots \infty}}}= $$

If $x^2+5 a x+6=0$ and $x^2+3 a x+2=0$ have a common root, then that common root is

If $\alpha, \beta, \gamma$ are roots of equations $x^3+a x^2+b x+x=0$, then $\alpha^{-1}+\beta^{-1}+\gamma^{-1}=$