Te folosesti de formulele de calcul prescurtat:
[tex](a+b) ^{2} = a^{2} + 2ab + b^{2} [/tex]
[tex](a-b) ^{2} = a ^{2} - 2ab +b ^{2} [/tex]
a)[tex](x- \sqrt{11} ) ^{2} = x^{2} - 2x \sqrt{11} + \sqrt{11} ^{2} = x^{2} - 2x \sqrt{11} + 11[/tex]
b) [tex](-x- \sqrt{11}) ^{2} = x^{2} - 2x \sqrt{11} - \sqrt{11}^{2} = x^{2} - 2x \sqrt{11}+11[/tex]
c) [tex](-x- \sqrt{11} ) ^{2} = x^{2} -2x \sqrt{11} + \sqrt{11} ^{2} =x^{2} -2x \sqrt{11} +11[/tex]
d)[tex](x+ \sqrt{11} ) ^{2} = x^{2} +2x \sqrt{11} + \sqrt{11} ^{2} =x^{2} +2x \sqrt{11} +11[/tex]
e)[tex]( \sqrt{11} -x ) ^{2} = \sqrt{11} ^{2} -2x \sqrt{11} + x^{2} =11-2x \sqrt{11} + x^{2} [/tex]
f)[tex]( \sqrt{11} +x ) ^{2} = \sqrt{11} ^{2} +2x \sqrt{11} + x^{2} =11+2x \sqrt{11} + x^{2} [/tex]
