Ответ:

  1. \(\sqrt{48}-\sqrt{12}+\sqrt{27}=4\sqrt3-2\sqrt3+3\sqrt3=5\sqrt3\).
  2. \(\sqrt{250}-\sqrt{90}+\sqrt{40}=5\sqrt{10}-3\sqrt{10}+2\sqrt{10}=4\sqrt{10}\).
  3. \(\sqrt{200}-3\sqrt{18}+\sqrt{50}=10\sqrt2-9\sqrt2+5\sqrt2=6\sqrt2\).
  4. \((2\sqrt5-\sqrt{10})^2=20-4\sqrt{50}+10=30-20\sqrt2\).
  5. \((5-\sqrt{14})(5+\sqrt{14})=25-14=11\).
  6. \((\sqrt{17}+2)(\sqrt{17}-2)=17-4=13\).