Simplify: (6x2−x+3)−(6x2+2x−3)(6x^2 - x + 3) - (6x^2 + 2x - 3)(6x2−x+3)−(6x2+2x−3).
−3x+6-3x + 6−3x+6
−3x-3x−3x
−3x−6-3x - 6−3x−6
12x2−3x12x^2 - 3x12x2−3x