Given $\displaystyle p(x)=x^3+2x^2-x-2 $

If $\displaystyle q(y)=y^6+2y^5-4y^4-6y^3+4y^2+2y-1$ , find the real number k such that

$\displaystyle

q(y)=y^3[(y-\frac{1}{y})^3+2(y-\frac{1}{y})^2-(y-\frac{1}{y})+k]

$, y is not 0 .

By using the substitution $\displaystyle x=y-\frac{1}{y}$ , show that the equation $\displaystyle q(y)=0$ can be transformed into the equation $\displaystyle p(x)=0$ .

THanks ..