Ответ:

  1. \(2\sqrt{8m}+\sqrt{18m}-\sqrt{50m}=4\sqrt{2m}+3\sqrt{2m}-5\sqrt{2m}=2\sqrt{2m}\).
  2. \(\sqrt{150}-\sqrt{54}+\sqrt{24}=5\sqrt6-3\sqrt6+2\sqrt6=4\sqrt6\).
  3. \(4\sqrt2-\sqrt{32}+3\sqrt{128}=4\sqrt2-4\sqrt2+24\sqrt2=24\sqrt2\).
  4. \((\sqrt7+1)^2=7+2\sqrt7+1=8+2\sqrt7\).
  5. \((\sqrt{19}-\sqrt5)(\sqrt{19}+\sqrt5)=19-5=14\).
  6. \((4\sqrt3-1)(4\sqrt3+1)=48-1=47\).

Ответ: 1) \(2\sqrt{2m}\); 2) \(4\sqrt6\); 3) \(24\sqrt2\); 4) \(8+2\sqrt7\); 5) \(14\); 6) \(47\).