Ответ:

  1. \(\sqrt{75\cdot234}=\sqrt{225\cdot78}=15\sqrt{78}\).
  2. \(\sqrt{2\cdot800}=\sqrt{1600}=40\).
  3. \(\sqrt{1.6\cdot12.1}=\sqrt{19.36}=4.4\).
  4. \(\sqrt{2890}=\sqrt{17^2\cdot10}=17\sqrt{10}\).