Simplify: (2x2−3)−(x2−3)(2x^2 - 3) - (x^2 - 3)(2x2−3)−(x2−3).
x2x^2x2
x2−6x^2 - 6x2−6
3x23x^23x2
x2+6x^2 + 6x2+6