X5+X7+1因式分解怎么弄
问题描述：
X5+X7+1因式分解怎么弄
答
x^7+x^5+1
=(x^7+x^6+x^5)+(1-x^6)
=x^5(x^2+x+1)+(1+x^3)(1-x)(1+x+x^2)
=(x^2+x+1)(x^5-x^4+x^3-x+1)