Ответ:

  1. \(7^5\cdot7^{12}:7^{14}=7^{5+12-14}=7^3=343\).
  2. \(\dfrac{(0.3)^9\cdot(0.3)^{18}}{(0.3)^{23}\cdot(0.3)^4}=(0.3)^{9+18-23-4}=(0.3)^0=1\).
  3. \(2^3\cdot128=8\cdot128=1024\).
  4. \(\dfrac{625\cdot5^3}{5^5}=\dfrac{5^4\cdot5^3}{5^5}=5^{4+3-5}=5^2=25\).

Ответ: 1) 343; 2) 1; 3) 1024; 4) 25.