Ответ:

  1. \[\frac{2^6\cdot(2^3)^5}{2^{18}}=\frac{2^6\cdot2^{15}}{2^{18}}=2^{6+15-18}=2^3=8.\]
  2. \[\frac{5^6\cdot125}{25^4}=\frac{5^6\cdot5^3}{(5^2)^4}=5^{6+3-8}=5.\]