Simplify the expression: x2−7x+12x2−9\frac{x^2 - 7x + 12}{x^2 - 9}x2−9x2−7x+12
x−4x+3\frac{x - 4}{x + 3}x+3x−4
x−3x+3\frac{x - 3}{x + 3}x+3x−3
x+4x−3\frac{x + 4}{x - 3}x−3x+4
x−4x−3\frac{x - 4}{x - 3}x−3x−4