Răspuns :
[tex]Se \ foloseste \ formula \ de calcul \ prscurtat \\ (a-b)^{2}=a ^{2}-2ab+b ^{2} \\ \\ (2- \sqrt{3}) ^{2}=2 ^{2}-2*2* \sqrt{3}+( \sqrt{3} )^{2}
\\ (2- \sqrt{3} ) ^{2}=4-4 \sqrt{3}+3
\\ (2- \sqrt{3})^{2} = \boxed{7-4 \sqrt{3}} [/tex]