Все расписать, . даю 50 поинтов

Question

Алгебра

Balladokelv

5 год назад

Все расписать, . даю 50 поинтов

ОТВЕТЫ

Milcho

Nov 22, 2020

$1)\frac{\sqrt{35}-\sqrt{15}}{\sqrt{14} -\sqrt{6}}=\frac{\sqrt{7*5}-\sqrt{3*5}}{\sqrt{7*2} -\sqrt{3*2}}=\frac{\sqrt{5}(\sqrt{7}-\sqrt{3})}{\sqrt{2}(\sqrt{7}-\sqrt{3})} =\frac{\sqrt{5} }{\sqrt{2}}=\frac{\sqrt{5}*\sqrt{2}}{\sqrt{2}*\sqrt{2}}=\frac{\sqrt{10}}{2}\\\\\\2)\frac{\sqrt{a}-\sqrt{b}}{a-b} =\frac{\sqrt{a}-\sqrt{b}}{(\sqrt{a})^{2}-(\sqrt{b})^{2}}=\frac{\sqrt{a}-\sqrt{b}}{(\sqrt{a}-\sqrt{b})(\sqrt{a}+\sqrt{b})}=\frac{1}{\sqrt{a}+\sqrt{b}}$

$3)\frac{x-2\sqrt{xy}+y}{x-y}=\frac{(\sqrt{x})^{2}-2\sqrt{xy}+(\sqrt{y})^{2}}{(\sqrt{x})^{2}-(\sqrt{y})^{2}} =\frac{(\sqrt{x}-\sqrt{y})^{2}}{(\sqrt{x}-\sqrt{y})(\sqrt{x}+\sqrt{y})}=\frac{\sqrt{x}-\sqrt{y}}{\sqrt{x}+\sqrt{y}}\\\\\\4)\frac{a-9}{\sqrt{a}+3 }=\frac{(\sqrt{a})^{2}-3^{2}}{\sqrt{a}+3}}=\frac{(\sqrt{a}+3)(\sqrt{a}-3)}{\sqrt{a}+3 }=\sqrt{a}-3$

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