Ответ:

[tex]1. 4\sqrt{2}+\sqrt{50}-\sqrt{18}=4\sqrt{2}+5\sqrt{2}-3\sqrt{2}=6\sqrt{2}[/tex]

[tex]2. \sqrt{3}\cdot (2\sqrt{3}+\sqrt{12})=\sqrt{3}\cdot (2\sqrt{3}+2\sqrt{3})=\sqrt{3}\cdot 4\sqrt{3}=12[/tex]

[tex]3. (\sqrt{5}-2)^2=5-4\sqrt{5}+4=9-4\sqrt{5}[/tex]

[tex]4. (\sqrt{3}-\sqrt{2})(\sqrt{3}+\sqrt{2})=\sqrt{3^2}-\sqrt{2^2}=1[/tex]

 

Возведем числа в квадрат:

[tex](3\sqrt{7})^2=63[/tex]

[tex](4\sqrt{5})^2=80[/tex]

[tex]3\sqrt{7}<4\sqrt{5}[/tex]