Answer:
4x^4+3x^2y^2+9y^2
(2x^2)^2 + 2×2x^2×3y^2 + (3y^2)^2 - 9
(2x^2 + 3y^2)^2 - (3)^2
(2x^2 +3y^2+3)(2x^2+3y^3-3)
