Question

me ajudem por favor, racionalize os denominadores

$\frac{3}{ \sqrt{5} }$

$\frac{7}{2 \sqrt{3} }$

$\frac{1}{4 - \sqrt{5} }$
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Answer 1

Resposta:

Explicação passo-a-passo:

i) $\frac{3}{\sqrt{5}}=\frac{3\sqrt{5}}{\sqrt{5}\sqrt{5}}=\frac{3\sqrt{5}}{5}$

ii) $\frac{7}{2\sqrt{3}}=\frac{7\sqrt{3}}{2\sqrt{3}\sqrt{3}}=\frac{7\sqrt{3}}{2.3}=\frac{7\sqrt{3}}{6}$

iii) $\frac{1}{4-\sqrt{5}}=\frac{1(4+\sqrt{5})}{(4-\sqrt{5})(4+\sqrt{5})}=\frac{4+\sqrt{5}}{4^{2}-(\sqrt{5})^{2}}=\frac{4+\sqrt{5}}{16-5}=\frac{4+\sqrt{5}}{11}$