$\begin{array}{l}\phantom{\phantom{;}x\phantom{;}-4;}{\phantom{;}x^{2}-x\phantom{;}+6\phantom{;}\phantom{;}}\\\phantom{;}x\phantom{;}-4\overline{\smash{)}\phantom{;}x^{3}-5x^{2}+10x\phantom{;}-15\phantom{;}\phantom{;}}\\\phantom{\phantom{;}x\phantom{;}-4;}\underline{-x^{3}+4x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-x^{3}+4x^{2};}-x^{2}+10x\phantom{;}-15\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-4-;x^n;}\underline{\phantom{;}x^{2}-4x\phantom{;}\phantom{-;x^n}}\\\phantom{;\phantom{;}x^{2}-4x\phantom{;}-;x^n;}\phantom{;}6x\phantom{;}-15\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-4-;x^n-;x^n;}\underline{-6x\phantom{;}+24\phantom{;}\phantom{;}}\\\phantom{;;-6x\phantom{;}+24\phantom{;}\phantom{;}-;x^n-;x^n;}\phantom{;}9\phantom{;}\phantom{;}\\\end{array}$

$x^{2}-x+6+\frac{9}{x-4}$