[tex]a)5+2 \sqrt{6} =( \sqrt{3}+ \sqrt{2})^{2} \\
5+2 \sqrt{6} =3+2+2 \sqrt{6} \\
5+2 \sqrt{6}=5+2 \sqrt{6} =>A \\ \\
b)7+2 \sqrt{6}=(1+\sqrt{6})^{2} \\
7+2\sqrt{6}=1+6+2 \sqrt{6} \\
7+2 \sqrt{6}=7+2 \sqrt{6}=>A \\ \\
c)11-6 \sqrt{2} =(3- \sqrt{2})^{2} \\
11-6 \sqrt{2}=9+2-6\sqrt{2} \\
11-6 \sqrt{2}=11- 6\sqrt{2}=>A \\ \\
d)7-4 \sqrt{3}=(2- \sqrt{3})^{2} \\
7-4 \sqrt{3}=4+3-4 \sqrt{3} \\
7-4 \sqrt{3}=7-4 \sqrt{3}=>A[/tex]
