Răspuns :
[tex](1+ \sqrt{7})^{2}+(1- \sqrt{7}) ^{2} = \\ 1^{2} + 2*1* \sqrt{7} + (\sqrt{7})^{2} + 1^{2} -2*1* \sqrt{7} + (\sqrt{7})^{2} = 2*1 + 7 + 7 = 16 \\
16 \ apartine \ N. [/tex]
16 \ apartine \ N. [/tex]