因式分解a2+（a+1）2+a2（a+1）2
问题描述：
因式分解a2+（a+1）2+a2（a+1）2
答
a^2+(a+1)^2+[a(a+1)]^2
=[a-(a+1)]^2+2a(a+1)+[a(a+1)]^2
=1+2a(a+1)+[a(a+1)]^2
=[a(a+1)+1]^2
=[a^2+a+1]^2