$\begin{array}{l}\phantom{\phantom{;}2m\phantom{;}-7;}{\phantom{;}4m^{2}+14m\phantom{;}+49\phantom{;}\phantom{;}}\\\phantom{;}2m\phantom{;}-7\overline{\smash{)}\phantom{;}8m^{3}\phantom{-;x^n}\phantom{-;x^n}-7\phantom{;}\phantom{;}}\\\phantom{\phantom{;}2m\phantom{;}-7;}\underline{-8m^{3}+28m^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-8m^{3}+28m^{2};}\phantom{;}28m^{2}\phantom{-;x^n}-7\phantom{;}\phantom{;}\\\phantom{\phantom{;}2m\phantom{;}-7-;x^n;}\underline{-28m^{2}+98m\phantom{;}\phantom{-;x^n}}\\\phantom{;-28m^{2}+98m\phantom{;}-;x^n;}\phantom{;}98m\phantom{;}-7\phantom{;}\phantom{;}\\\phantom{\phantom{;}2m\phantom{;}-7-;x^n-;x^n;}\underline{-98m\phantom{;}+343\phantom{;}\phantom{;}}\\\phantom{;;-98m\phantom{;}+343\phantom{;}\phantom{;}-;x^n-;x^n;}\phantom{;}336\phantom{;}\phantom{;}\\\end{array}$

$4m^{2}+14m+49+\frac{336}{2m-7}$