求因式分解解题过程a^(n+2)-18a^n+81a^(n-2)=
问题描述:
求因式分解解题过程a^(n+2)-18a^n+81a^(n-2)=
答
a^(n+2)-18a^n+81a^(n-2)
=a^(n-2)*(a^4-18a^2+81)
=a^(n-2)*[(a^2-9)]^2