Объяснение:
(3-m)(3+m)(9+m²)-(m-2)(m²+3m+4)=
=(9-m²)(9+m²)-(m³+3m²+4m-2m²+6m-8=
=81-m^4-(m³+m²+10m-8)=
=81-m^4-m³-m^2-10m+8=
=-m^4-m³-m²-10m+89
