Question

Помогите с алгеброй пожалуйста срочно 2-4

Answer 1

$\frac{\sqrt{a}+\sqrt{b}}{a\sqrt{a}+b\sqrt{b}}=\frac{\sqrt{a} +\sqrt{b}}{(\sqrt{a})^{3}+(\sqrt{b})^{3}}=\frac{\sqrt{a}+\sqrt{b}}{(\sqrt{a} +\sqrt{b})(a-\sqrt{ab}+b)}=\frac{1}{a-\sqrt{ab} +b} \\\\\frac{2\sqrt{2}-x\sqrt{x}}{2+\sqrt{2x} +x} =\frac{(\sqrt{2})^{3}-(\sqrt{x})^{3}}{2+\sqrt{2x}+x } =\frac{(\sqrt{2}-\sqrt{x})(2+\sqrt{2x}+x)}{2+\sqrt{2x}+x } =\sqrt{2}-\sqrt{x}\\\\\frac{a-\sqrt{3a}+3 }{a\sqrt{a} +3\sqrt{3} }=\frac{a-\sqrt{3a}+3 }{(\sqrt{a})^{3} +(\sqrt{3})^{3}}=$$=\frac{a-\sqrt{3a} +3}{(\sqrt{a}+\sqrt{3} )(a-\sqrt{3a}+3)}=\frac{1}{\sqrt{a} +\sqrt{3} }$