Prove that: $$ q^{2} \frac{\left(1-q^{n-1} ight)\left(1-q^{n-2} ight)}{(1-9) \left(1- q^{2} ight)}+\frac{\left(1-q^{n-1} ight)}{(1-9)} $$ is a polynomial in $\mathrm{q}$ CS.VS. 1442|