\[ (c^3)^5 \cdot c^{-4} = c^{3 \cdot 5} \cdot c^{-4} = c^{15} \cdot c^{-4} = c^{15 + (-4)} = c^{11} \]
\[ (c^5)^4 \cdot c^{-7} = c^{5 \cdot 4} \cdot c^{-7} = c^{20} \cdot c^{-7} = c^{20 + (-7)} = c^{13} \]
\[ \frac{c^{11}}{c^{13}} = c^{11 - 13} = c^{-2} \]
\[ (5^{-1})^{-2} = 5^{(-1) \cdot (-2)} = 5^2 \]
\[ 5^2 = 25 \]
Ответ: 25