(a+1)^2*(a-1)^2*(a+1)^2 如何计算（简便运算,
问题描述：
(a+1)^2*(a-1)^2*(a+1)^2 如何计算（简便运算,
答
(a+1)^2*(a-1)^2*(a+1)^2
=(a^2-1)^2*(a+1)^2
=(a^4-2a^2+1)*(a^2+2a+1)
=a^6+2a^5+a^4-4a^4-4a^3-2a^2+a^2+2a+1
=a^6+2a^5-3a^4-4a^3-a^2+2a+1