$\begin{array}{l}\phantom{\phantom{;}x\phantom{;}-1;}{\phantom{;}3x^{3}+3x^{2}+3x\phantom{;}+8\phantom{;}\phantom{;}}\\\phantom{;}x\phantom{;}-1\overline{\smash{)}\phantom{;}3x^{4}\phantom{-;x^n}\phantom{-;x^n}+5x\phantom{;}-18\phantom{;}\phantom{;}}\\\phantom{\phantom{;}x\phantom{;}-1;}\underline{-3x^{4}+3x^{3}\phantom{-;x^n}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-3x^{4}+3x^{3};}\phantom{;}3x^{3}\phantom{-;x^n}+5x\phantom{;}-18\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-1-;x^n;}\underline{-3x^{3}+3x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{;-3x^{3}+3x^{2}-;x^n;}\phantom{;}3x^{2}+5x\phantom{;}-18\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-1-;x^n-;x^n;}\underline{-3x^{2}+3x\phantom{;}\phantom{-;x^n}}\\\phantom{;;-3x^{2}+3x\phantom{;}-;x^n-;x^n;}\phantom{;}8x\phantom{;}-18\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-1-;x^n-;x^n-;x^n;}\underline{-8x\phantom{;}+8\phantom{;}\phantom{;}}\\\phantom{;;;-8x\phantom{;}+8\phantom{;}\phantom{;}-;x^n-;x^n-;x^n;}-10\phantom{;}\phantom{;}\\\end{array}$

$3x^{3}+3x^{2}+3x+8+\frac{-10}{x-1}$