(а^3-9)(а^6+9а^3+81)-а^9-729=...

Question

(а^3-9)(а^6+9а^3+81)-а^9-729=...

Answer 1

(а^3-9)(а^6+9а^3+81)-а^9-729=a^9+a^6⋅9+a^3⋅81−9a^6−81a^3−729−a^9−729=9a^6−9a^6−1458=−1458