(4-\sqrt{5} )^{2} =4^{2} -2*4\sqrt{5} +\sqrt{5}^{2} =16-8\sqrt{5} +5=21-8\sqrt{5} \\
(\sqrt{3}-3)^{2} =\sqrt{3}^{2} -6\sqrt{3} +3^{2} =3-6\sqrt{3} +9=12-6\sqrt{3}\\
(\sqrt{10}-1)^{2} =10-2\sqrt{10} +1 = 11-2\sqrt{10}\\
(6-\sqrt{6} ) ^{2}=36-12\sqrt{6} + 6 = 42-12\sqrt{6}\\
(\sqrt{8} -4)^{2} =8-8\sqrt{8} +8=16-8\sqrt{8}=16-16\sqrt{2} \\\
(\sqrt{7} -\sqrt{6})^{2} =7-2\sqrt{42} +6 = 13-2\sqrt{42}\\\\
(\sqrt{12} -\sqrt{2} ) ^{2} =12-2\sqrt{24} +2=14-4\sqrt{6}\\
