Let a and b be the roots of equation x2 – 6x – 2 = 0. If an = a n – b n , for n ³ 1, then the value of 10 8 9 a 2a 2a – is equal to:

Let $\alpha$ and $\beta$ be the roots of equation $x^{2}-6 x-2=0$. If $a_{n}=$ $\alpha^{\mathrm{n}}-\beta^{\mathrm{n}}$, for $\mathrm{n} \geq 1$, then the value of $\frac{\mathrm{a}_{10}-2 \mathrm{a}_{8}}{2 \mathrm{a}_{9}}$ is equal to: