Ta có:
[tex]\frac{2016-2015+\sqrt{2015.2016}(\sqrt{2016}-\sqrt{2015})}{\sqrt{2015}+\sqrt{2016}+\sqrt{2015.2016}}[/TEX]
[TEX]=\frac{(\sqrt{2016}-\sqrt{2015})(\sqrt{2016}+\sqrt{2015})+\sqrt{2015.2016}(\sqrt{2016}-\sqrt{2015}){\sqrt{2015}+\sqrt{2016}+\sqrt{2015.2016}[/TEX]
[TEX]=\sqrt{2016}-\sqrt{2015}[/tex]