X'n+3-X'nY'3==x^n(x-y)(x^2+xy+y^2)
A'3+27=(A+3)(A^2-3A+9)
27X'3+8=(3x+2)(9x^2-6x+4)
(X+2Y)'2-(X-2Y)'2=2x(4y)=8xy
X'2+6ax+9a'2=(x+3a)^2