(1+23)2=1+43+12=13+43(1 + 2\sqrt{3})^{2} = 1 + 4\sqrt{3} + 12 = 13 + 4\sqrt{3}(1+23)2=1+43+12=13+43
(1−23)2=1−43+12=13−43(1 - 2\sqrt{3})^{2} = 1 - 4\sqrt{3} + 12 = 13 - 4\sqrt{3}(1−23)2=1−43+12=13−43
13+43−(13−43)=13+43−13+4313 + 4\sqrt{3} - (13 - 4\sqrt{3}) = 13 + 4\sqrt{3} - 13 + 4\sqrt{3}13+43−(13−43)=13+43−13+43
= 838\sqrt{3}83
