$=2x^{2}+\frac{-10x^{2}-3x-6}{x+3}$
Divide $ \frac{-10x^{2}-3x-6}{x+3}:{\quad}\frac{-10x^{2}-3x-6}{x+3}=-10x+\frac{27x-6}{x+3}$$=2x^{2}-10x+\frac{27x-6}{x+3}$
Divide $ \frac{27x-6}{x+3}:{\quad}\frac{27x-6}{x+3}=27+\frac{-87}{x+3}$$=2x^{2}-10x+27+\frac{-87}{x+3}$
Simplify$=2x^{2}-10x+27-\frac{87}{x+3}$