$\begin{array}{l}\phantom{\phantom{;}4x\phantom{;}-1;}{\phantom{;}3x^{2}+2x\phantom{;}-4\phantom{;}\phantom{;}}\\\phantom{;}4x\phantom{;}-1\overline{\smash{)}\phantom{;}12x^{3}+5x^{2}-18x\phantom{;}-3\phantom{;}\phantom{;}}\\\phantom{\phantom{;}4x\phantom{;}-1;}\underline{-12x^{3}+3x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-12x^{3}+3x^{2};}\phantom{;}8x^{2}-18x\phantom{;}-3\phantom{;}\phantom{;}\\\phantom{\phantom{;}4x\phantom{;}-1-;x^n;}\underline{-8x^{2}+2x\phantom{;}\phantom{-;x^n}}\\\phantom{;-8x^{2}+2x\phantom{;}-;x^n;}-16x\phantom{;}-3\phantom{;}\phantom{;}\\\phantom{\phantom{;}4x\phantom{;}-1-;x^n-;x^n;}\underline{\phantom{;}16x\phantom{;}-4\phantom{;}\phantom{;}}\\\phantom{;;\phantom{;}16x\phantom{;}-4\phantom{;}\phantom{;}-;x^n-;x^n;}-7\phantom{;}\phantom{;}\\\end{array}$

$3x^{2}+2x-4+\frac{-7}{4x-1}$