a^n+2-6a^n+5a^n-2(n>2且n为整数

问题描述:

a^n+2-6a^n+5a^n-2(n>2且n为整数

a^n+2-6a^n+5a^n-2
=a^(n-2)[a^4-6a^2+5]
=a^(n-2)(a^2-1)(a^2-5)
=a^(n-2)(a-1)(a+1)(a^2-5)