Question

Помогите пожалуйста....

Answer 1

Ответ:

картинка 1:

$\frac{2+\sqrt{2} }{\sqrt{10}+\sqrt{5} }=\frac{\sqrt{2}(\sqrt{2}+1) }{\sqrt{5}(\sqrt{2}+1) } =\frac{\sqrt{2}}{\sqrt{5}}=\frac{\sqrt{10}}{5}$

картинка 2:

$\frac{2}{5} \sqrt{75}+\sqrt{2} (\sqrt{2} -\sqrt{6}) =\frac{2}{5}*5\sqrt{3} +2-\sqrt{12} =2\sqrt{3} +2-2\sqrt{3} =2$

$(\sqrt{7} -\sqrt{2} )^2=7-2\sqrt{14}+2=9-2\sqrt{14}$