$\begin{array}{l}\phantom{\phantom{;}x\phantom{;}+2;}{-3x^{2}+16x\phantom{;}-21\phantom{;}\phantom{;}}\\\phantom{;}x\phantom{;}+2\overline{\smash{)}-3x^{3}+10x^{2}+11x\phantom{;}+6\phantom{;}\phantom{;}}\\\phantom{\phantom{;}x\phantom{;}+2;}\underline{\phantom{;}3x^{3}+6x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{\phantom{;}3x^{3}+6x^{2};}\phantom{;}16x^{2}+11x\phantom{;}+6\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}+2-;x^n;}\underline{-16x^{2}-32x\phantom{;}\phantom{-;x^n}}\\\phantom{;-16x^{2}-32x\phantom{;}-;x^n;}-21x\phantom{;}+6\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}+2-;x^n-;x^n;}\underline{\phantom{;}21x\phantom{;}+42\phantom{;}\phantom{;}}\\\phantom{;;\phantom{;}21x\phantom{;}+42\phantom{;}\phantom{;}-;x^n-;x^n;}\phantom{;}48\phantom{;}\phantom{;}\\\end{array}$

$-3x^{2}+16x-21+\frac{48}{x+2}$