6)8p-4 q-1 -2 (16p-693)3.

6) $$ (\frac{8p^{-4}}{q^{-1}})^{-2} \cdot (16p^{-6}q^{3})^{3} = (\frac{q}{8p^{-4}})^{2} \cdot 16^{3}p^{-18}q^{9} = \frac{q^{2}}{64p^{-8}} \cdot 16^{3}p^{-18}q^{9} = \frac{q^{2}p^{8}}{64} \cdot 16^{3}p^{-18}q^{9} = \frac{16^{3}}{64} \cdot p^{8-18} \cdot q^{2+9} = \frac{16 \cdot 16 \cdot 16}{64} \cdot p^{-10} \cdot q^{11} = \frac{16 \cdot 16}{4} \cdot \frac{q^{11}}{p^{10}} = 4 \cdot 16 \cdot \frac{q^{11}}{p^{10}} = \frac{64q^{11}}{p^{10}} $$

Ответ: $$ \frac{64q^{11}}{p^{10}} $$