x的五次方-1因式分解
问题描述：
x的五次方-1因式分解
答
x的五次方-1
=x^5-x^3+x^3-1
=x^3(x^2-1)+(x-1)(x^2+x+1)
=x^3(x+1)(x-1)+(x-1)(x^2+x+1)
=(x-1)(x^4+x^3+x^2+x+1)