$\begin{array}{l}\phantom{-2x\phantom{;}+1;}{\frac{5}{-2}x^{2}+\frac{2.5}{-2}x\phantom{;}+\frac{1.25}{-2}\phantom{;}\phantom{;}}\\-2x\phantom{;}+1\overline{\smash{)}\phantom{;}5x^{3}\phantom{-;x^n}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-2x\phantom{;}+1;}\underline{-5x^{3}+2.5x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-5x^{3}+2.5x^{2};}\phantom{;}2.5x^{2}\phantom{-;x^n}\phantom{-;x^n}\\\phantom{-2x\phantom{;}+1-;x^n;}\underline{-2.5x^{2}+1.25x\phantom{;}\phantom{-;x^n}}\\\phantom{;-2.5x^{2}+1.25x\phantom{;}-;x^n;}\phantom{;}1.25x\phantom{;}\phantom{-;x^n}\\\phantom{-2x\phantom{;}+1-;x^n-;x^n;}\underline{-1.25x\phantom{;}+0.625\phantom{;}\phantom{;}}\\\phantom{;;-1.25x\phantom{;}+0.625\phantom{;}\phantom{;}-;x^n-;x^n;}\phantom{;}0.625\phantom{;}\phantom{;}\\\end{array}$

$\frac{5}{-2}x^{2}+\frac{2.5}{-2}x+\frac{1.25}{-2}+\frac{0.625}{1-2x}$