Simplify: x2+3xx2−9\frac{x^2 + 3x}{x^2 - 9}x2−9x2+3x (assume x≠3,−3x \neq 3, -3x=3,−3).
x−3x\frac{x-3}{x}xx−3
x+3x−3\frac{x+3}{x-3}x−3x+3
xx+3\frac{x}{x+3}x+3x
xx−3\frac{x}{x-3}x−3x