1,\(=\sqrt{5-2.\sqrt{2}.\sqrt{5}.2}-\sqrt{5-2\sqrt{5}+1}\\ =\sqrt{\left(\sqrt{5}-\sqrt{2}\right)^2}-\sqrt{\left(\sqrt{5}-1\right)}^2\\ =\left|\sqrt{5}-\sqrt{2}\right|-\left|\sqrt{5}-1\right|\\ =\sqrt{5}-\sqrt{2}-\sqrt{5}+1\\ =1-\sqrt{2}\)
\(2,=\sqrt{24-2.2\sqrt{6}.3+9}-\sqrt{9-2.3.\sqrt{6}+6}\\ =\sqrt{\left(2\sqrt{6}-3\right)^2}-\sqrt{\left(3-\sqrt{6}\right)}\\ =\left|2\sqrt{6}-3\right|-\left|3-\sqrt{6}\right|\\ =2\sqrt{6}-3-3+\sqrt{6}\\ =3\sqrt{6}-6\)
\(3,=\sqrt{4-2.2.\sqrt{5}+5}+\sqrt{7-2.\sqrt{7}.\sqrt{5}+5}\\ =\sqrt{\left(2-\sqrt{5}\right)^2}+\sqrt{\left(\sqrt{7}-\sqrt{5}\right)^2}\\ =\left|2-\sqrt{5}\right|+\left|\sqrt{7}-\sqrt{5}\right|\\ =\sqrt{5}-2+\sqrt{7}-\sqrt{5}\\ =\sqrt{7}-2\)
