(a-b)³=a³-3a²b+3ab²-b³
(a+b)³=a³+3a²b+3ab²+b³
可以利用二项式定理将其展开
(a-b)³=a³-3a²b+3ab²-b³
(a+b)³=a³+3a²b+3ab²+b³
(a+b)^3=a^3+3a^2b+3ab^2+b^3
(a-b)^3=a^3-3a^2b+3ab^2-b^3
{(a-b) (a+b)}^3
=(a^2-b^2)^3
=a^6-3a^4b^2+3a^2b^4-b^6
(a+b)^3=a^3+3a^2b+3ab^2+b^3
(a-b)^3=a^3-3a^2b+3ab^2-b^3