Ответ:

  1. \(\sqrt{50}=\sqrt{25\cdot2}=5\sqrt2\).
  2. \(\sqrt{72}=\sqrt{36\cdot2}=6\sqrt2\).
  3. \(\sqrt{112}=\sqrt{16\cdot7}=4\sqrt7\).
  4. \(\sqrt{176}=\sqrt{16\cdot11}=4\sqrt{11}\).
  5. Так как \(b\ge0\), \(\sqrt{75b^5}=\sqrt{25b^4\cdot3b}=5b^2\sqrt{3b}\).
  6. Так как \(x\ge0\), \(\sqrt{128x^9}=\sqrt{64x^8\cdot2x}=8x^4\sqrt{2x}\).

Ответ: 3) \(5\sqrt2\); 4) \(6\sqrt2\); 7) \(4\sqrt7\); 8) \(4\sqrt{11}\); 11) \(5b^2\sqrt{3b}\); 12) \(8x^4\sqrt{2x}\).