2x分之(x+2)*(x^2+5x+6)分之(x^3-3x^2)÷(x^2+2x-3)分之(x^3-9x)
=2x分之(x+2)*(x+2)(x+3)分之x^2(x-3)*x(x+3)(x-3)分之(x+3)(x-1)
=2(x+3)分之(x-1)
=(2x+6)分之(x-1)