Answer :

4m^4-5m^2

Basically you divide each term by the denominator
this is akin to splittting fraction. Just as you can add 2/5 and 4/5 to get (2+4)/5, like wise you can split apart fractions. By doing this, you get two fractions and you can evaluate them individually
[tex]\frac{8m^{7} - 10m^{5}}{2m^{3}} = \frac{8m^{7}}{2m^{3}} - \frac{10m^{5}}{2m^{3}} = 4m^{4} - 5m^{2}[/tex]