$\begin{array}{l}\phantom{\phantom{;}x\phantom{;}-4;}{-3x^{2}-4x\phantom{;}+4\phantom{;}\phantom{;}}\\\phantom{;}x\phantom{;}-4\overline{\smash{)}-3x^{3}+8x^{2}+20x\phantom{;}-14\phantom{;}\phantom{;}}\\\phantom{\phantom{;}x\phantom{;}-4;}\underline{\phantom{;}3x^{3}-12x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{\phantom{;}3x^{3}-12x^{2};}-4x^{2}+20x\phantom{;}-14\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-4-;x^n;}\underline{\phantom{;}4x^{2}-16x\phantom{;}\phantom{-;x^n}}\\\phantom{;\phantom{;}4x^{2}-16x\phantom{;}-;x^n;}\phantom{;}4x\phantom{;}-14\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-4-;x^n-;x^n;}\underline{-4x\phantom{;}+16\phantom{;}\phantom{;}}\\\phantom{;;-4x\phantom{;}+16\phantom{;}\phantom{;}-;x^n-;x^n;}\phantom{;}2\phantom{;}\phantom{;}\\\end{array}$

$-3x^{2}-4x+4+\frac{2}{x-4}$