Сократите дробь: (25m^2-9n^2)/(12n+20m).

\[\frac{25m^{2} - 9n^{2}}{12n + 20m} = \frac{(5m - 3n)(5m + 3n)}{4 \cdot (3n + 5m)} =\]

\[= \frac{5m - 3n}{4}\]