\(6-\sqrt{17}=\sqrt{36}-\sqrt{17}>\sqrt{31}-\sqrt{17}>\sqrt{31}-\sqrt{19}\)

HAY  \(6-\sqrt{17}>\sqrt{31}-\sqrt{19}\)

\(\left(\sqrt{26}+3\right)^2=35+6\sqrt{26}\)

\(\left(\sqrt{63}\right)^2=63=35+28\)

mà \(6\sqrt{26}>28\)

nên \(\sqrt{26}+3>\sqrt{63}\)

\(\sqrt{2019}-\sqrt{2017}\approx0,022\) \(< \sqrt{19}-\sqrt{17}\approx0,23\)

chắc vậy :))

Vì \(180< 441\)\(\Rightarrow\)\(\sqrt{180}< \sqrt{441}\)

                               \(\Leftrightarrow\)\(14+6\sqrt{5}< 14+21\)

                               \(\Leftrightarrow\)\(9+6\sqrt{5}+5< 35\)

                               \(\Leftrightarrow\)\(\left(\sqrt{9}+\sqrt{5}\right)^2< 35\)

                               \(\Leftrightarrow\)\(\sqrt{9}+\sqrt{5}< \sqrt{35}\)

Vậy \(\sqrt{9}+\sqrt{5}< \sqrt{35}\)

Giả sử \(8>\sqrt{15}+\sqrt{17}\)

\(\Leftrightarrow64>32+2\sqrt{15×17}\)

\(\Leftrightarrow16>\sqrt{\left(16-1\right)\left(16+1\right)}=\sqrt{16^2-1}\left(dung\right)\)

Vậy \(8>\sqrt{15}+\sqrt{17}\)

dsadasdsadsadsasddấdasdasdadấdadsdsđasdasđ^{dsaádasdasdádaddadadaddadadaddâdadaad}

\(\sqrt{2016}-\sqrt{2015}=\dfrac{1}{\sqrt{2016}+\sqrt{2015}}\)

\(\sqrt{2015}-\sqrt{2014}=\dfrac{1}{\sqrt{2015}+\sqrt{2014}}\)

căn 2016+căn 2015>căn 2015+căn 2014

=>1/(căn 2016+căn 2015)<1/(căn 2015+căn 2014)

=>căn 2016-căn 2015<căn 2015-căn 2014