1、(3a+b)^2=9a^2+6ab+b^2
(a+b)^2=a^2+2ab+b^2
(a-b)^2=a^2-2ab+b^2
2、(x+y+3)^2=x^2+y^2+9+2xy+6x+6y
(a+b+c)^2=a^2+b^2+c^2+2ab+2ac+2bc
(a-b-c)^2=a^2+b^2+c^2-2ab-2ac+2bc
3、(x+2)(x^2-2x+4)=x^3+8
(a+b)(a^2-ab+b^2)=a^3+b^3
4、(2x-1)(4x^2+2x+1)=8x^3-1
(a-b)(a^2+ab+b^2)=a^3-b^3
5、(x+2)^3=x^3+6x^2+12x+8
(a+b)^3=a^3+3a^2*b+3ab^2+b^3
6、(x-2)^3=x^3-6x^2+12x-8
(a-b)^3=a^3-3a^2*b+3ab^2-b^3