Ответ:

  1. \(2^{20} : (2^8)^2 = 2^{20-16} = 2^4 = 16\).
  2. \((11^3)^4 : (11^5)^2 = 11^{12-10} = 11^2 = 121\).
  3. \(7^9 \cdot (7^2)^6 : 7^{19} = 7^{9+12-19} = 7^2 = 49\).
  4. \(16^2 \cdot 8 = (2^4)^2 \cdot 2^3 = 2^{8+3} = 2^{11} = 2048\).
  5. \(\dfrac{10^{17} \cdot (10^2)^3}{(10^3)^4 \cdot 10^9} = 10^{17+6-12-9} = 10^2 = 100\).
  6. \(\dfrac{9^3 \cdot 81^2}{3^{12}} = 3^{6+8-12} = 3^2 = 9\).