4.4. Упростите: 1) \((b^4)^6:(b^5)^4\); 2) \((b^{16})^4:(b^3)^{20}\); 3) \((b^9)^{12}:(b^{10})^{10}\); 4) \((b^{30})^3:(b^4)^{20}\); 5) \((b^3)^7\cdot(b^5)^5\); 6) \((b^7)^6:(b^8)^5\).

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

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