2. Упростите выражение: 1) \(\frac{3a}{a-3}+\frac{a+5}{6-2a}\); \(\frac{5a}{5a+a^2}\); 2) \(\left(\frac{a+4}{a-4}-\frac{a-4}{a+4}\right):\frac{48a}{16-a^2}\).

1. \[\frac{3a}{a-3}+\frac{a+5}{6-2a}=\frac{3a}{a-3}-\frac{a+5}{2(a-3)}=\frac{6a-a-5}{2(a-3)}=\frac{5(a-1)}{2(a-3)}.\]
   \[\frac{5a}{5a+a^2}=\frac{5a}{a(a+5)}=\frac{5}{a+5}.\]
2. \[\left(\frac{a+4}{a-4}-\frac{a-4}{a+4}\right):\frac{48a}{16-a^2}\]
   \[=\frac{(a+4)^2-(a-4)^2}{(a-4)(a+4)}\cdot\frac{16-a^2}{48a}=\frac{16a}{a^2-16}\cdot\frac{-(a^2-16)}{48a}=-\frac13.\]

Ответ: 1) \(\frac{5(a-1)}{2(a-3)}\); \(\frac{5}{a+5}\); 2) \(-\frac13\).