求8(x+y)^3+1因式分解
问题描述：
求8(x+y)^3+1因式分解
答
8(x+y)^3+1
=8[(x+y)^3+1/8]
=8[(x+y)^3+(1/2)^3]
=8(x+y-1/2)[(x+y)^2+1/2*(x+y)+1/4]