(a+b)^2=a^2+2ab+b^2
(a-b)^2=a^2-2ab+b^2
(a+b)^3=a^3+3a^2b+3ab^2+b^3
(a-b)^3=a^303a^2b+3ab^20b^3
(a+b)(a-b)=a^2-b^2
a^3+b^3=(a+b)(a^2-ab+b^2)
a^3-b^3=(a-b)(a^2+ab+b^2)
(a+b+c)^2=a^2+b^2+c^2+2ab+2ac+2bc