9a^2-12ab+4b^2
X^6-4X^3+4
a^10+8a^5+16
y^8-2y^4Z^3+Z^6
X^4+6X^2+9
(3a-2b)^2
(a^5+4)^2
(X^3-2)^2
(y^4-Z^3)^2
(X^2+3)^2
