$\begin{array}{l}\phantom{\phantom{;}5x\phantom{;}-4;}{\phantom{;}10x^{2}+10x\phantom{;}+1\phantom{;}\phantom{;}}\\\phantom{;}5x\phantom{;}-4\overline{\smash{)}\phantom{;}50x^{3}+10x^{2}-35x\phantom{;}-7\phantom{;}\phantom{;}}\\\phantom{\phantom{;}5x\phantom{;}-4;}\underline{-50x^{3}+40x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-50x^{3}+40x^{2};}\phantom{;}50x^{2}-35x\phantom{;}-7\phantom{;}\phantom{;}\\\phantom{\phantom{;}5x\phantom{;}-4-;x^n;}\underline{-50x^{2}+40x\phantom{;}\phantom{-;x^n}}\\\phantom{;-50x^{2}+40x\phantom{;}-;x^n;}\phantom{;}5x\phantom{;}-7\phantom{;}\phantom{;}\\\phantom{\phantom{;}5x\phantom{;}-4-;x^n-;x^n;}\underline{-5x\phantom{;}+4\phantom{;}\phantom{;}}\\\phantom{;;-5x\phantom{;}+4\phantom{;}\phantom{;}-;x^n-;x^n;}-3\phantom{;}\phantom{;}\\\end{array}$

$10x^{2}+10x+1+\frac{-3}{5x-4}$