Выполните действия: (3a-3c)/a:(a^2-c^2).

\[\frac{3a - 3c}{a}\ \ :\left( a^{2} - c^{2} \right) = \frac{3 \cdot (a - c)}{a(a - c)(a + c)} =\]

\[= \frac{3}{a^{2} + ac}\ \]