Ответ:

  1. \((b^4)^6\cdot(b^5)^4=b^{24+20}=b^{44}\).
  2. \((b^{16})^4:(b^3)^{20}=b^{64-60}=b^4\).
  3. \((b^9)^{12}:(b^{10})^{10}=b^{108-100}=b^8\).
  4. \((b^{30})^3:(b^4)^{20}=b^{90-80}=b^{10}\).
  5. \((b^3)^7\cdot(b^5)^5=b^{21+25}=b^{46}\).
  6. \((b^7)^6:(b^8)^5=b^{42-40}=b^2\).

Ответ: 1) \(b^{44}\); 2) \(b^4\); 3) \(b^8\); 4) \(b^{10}\); 5) \(b^{46}\); 6) \(b^2\).