$\begin{array}{l}\phantom{\phantom{;}x\phantom{;}-2;}{\phantom{;}x^{2}-10x\phantom{;}-20\phantom{;}\phantom{;}}\\\phantom{;}x\phantom{;}-2\overline{\smash{)}\phantom{;}x^{3}-12x^{2}\phantom{-;x^n}-42\phantom{;}\phantom{;}}\\\phantom{\phantom{;}x\phantom{;}-2;}\underline{-x^{3}+2x^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-x^{3}+2x^{2};}-10x^{2}\phantom{-;x^n}-42\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-2-;x^n;}\underline{\phantom{;}10x^{2}-20x\phantom{;}\phantom{-;x^n}}\\\phantom{;\phantom{;}10x^{2}-20x\phantom{;}-;x^n;}-20x\phantom{;}-42\phantom{;}\phantom{;}\\\phantom{\phantom{;}x\phantom{;}-2-;x^n-;x^n;}\underline{\phantom{;}20x\phantom{;}-40\phantom{;}\phantom{;}}\\\phantom{;;\phantom{;}20x\phantom{;}-40\phantom{;}\phantom{;}-;x^n-;x^n;}-82\phantom{;}\phantom{;}\\\end{array}$

$x^{2}-10x-20+\frac{-82}{x-2}$