$\begin{array}{l}\phantom{\phantom{;}2x\phantom{;}+1;}{\phantom{;}x^{2}+10x\phantom{;}-5\phantom{;}\phantom{;}}\\\phantom{;}2x\phantom{;}+1\overline{\smash{)}\phantom{;}2x^{3}+21x^{2}\phantom{-;x^n}+2\phantom{;}\phantom{;}}\\\phantom{\phantom{;}2x\phantom{;}+1;}\underline{-2x^{3}-x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-2x^{3}-x^{2};}\phantom{;}20x^{2}\phantom{-;x^n}+2\phantom{;}\phantom{;}\\\phantom{\phantom{;}2x\phantom{;}+1-;x^n;}\underline{-20x^{2}-10x\phantom{;}\phantom{-;x^n}}\\\phantom{;-20x^{2}-10x\phantom{;}-;x^n;}-10x\phantom{;}+2\phantom{;}\phantom{;}\\\phantom{\phantom{;}2x\phantom{;}+1-;x^n-;x^n;}\underline{\phantom{;}10x\phantom{;}+5\phantom{;}\phantom{;}}\\\phantom{;;\phantom{;}10x\phantom{;}+5\phantom{;}\phantom{;}-;x^n-;x^n;}\phantom{;}7\phantom{;}\phantom{;}\\\end{array}$

$x^{2}+10x-5+\frac{7}{2x+1}$