\(A=\dfrac{4x\sqrt{x}+3x+9+x-9}{\left(\sqrt{x}+2\right)\left(\sqrt{x}+3\right)}:\dfrac{x+2\sqrt{x}-4\sqrt{x}-3}{\left(\sqrt{x}+3\right)\left(\sqrt{x}+2\right)}\)
\(=\dfrac{4x\sqrt{x}+4x}{x-2\sqrt{x}-3}=\dfrac{4x\left(\sqrt{x}+1\right)}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+1\right)}=\dfrac{4x}{\sqrt{x}-3}\)