Question

очень срочно нужно!!!!!​

Answer 1

$\displaystyle\Bigg(\dfrac{\sqrt{n}}{\sqrt{m}+\sqrt{n}}-\dfrac{\sqrt{n}-\sqrt{m}}{\sqrt{n}}\Bigg)\div\dfrac{\sqrt{m}}{\sqrt{n}}=\dfrac{(\sqrt{n})^2-(\sqrt{n}-\sqrt{m})(\sqrt{m}+\sqrt{n})}{\sqrt{n}(\sqrt{m}+\sqrt{n})}\cdot\dfrac{\sqrt{n}}{\sqrt{m}}=\\\\\\=\dfrac{n-(n-m)}{\sqrt{m}+\sqrt{n}}\cdot\dfrac{1}{\sqrt{m}}=\dfrac{m}{\sqrt{m}(\sqrt{m}+\sqrt{n})}=\dfrac{m}{m+\sqrt{mn}}=\dfrac{m(m-\sqrt{mn})}{m(m-n)}=\\\\\\=\dfrac{m-\sqrt{mn}}{m-n}$