Ответ: 4
\[\frac{a^{-11} \cdot a^4}{a^{-3}} = \frac{a^{-11+4}}{a^{-3}} = \frac{a^{-7}}{a^{-3}} = a^{-7 - (-3)} = a^{-7+3} = a^{-4}\]
\[a^{-4} = (\frac{1}{2})^{-4} = (2^{-1})^{-4} = 2^{(-1) \cdot (-4)} = 2^4\]
\[2^4 = 2 \cdot 2 \cdot 2 \cdot 2 = 16\]
Ответ: 16