$$\frac{4x^{2}+18x+9}{4x^{2}-9}-\frac{2x^{2}+3x+2}{2x^{2}-2x-3}$$
$\frac{16x^{3}-20x^{2}-45x-9}{\left(4x^{2}-9\right)\left(2x^{2}-2x-3\right)}$
