Question

Calcular o valor das expressoes:
 a)  (√3+√5 + √3-√5)²

b)   $\frac{4}{√3-1} - \frac{4}{√3+1}$

Answer 1

a) 
$( \sqrt{3} + \sqrt{5} + \sqrt{3} - \sqrt{5})^2$


$2( \sqrt{3} * \sqrt{3}})^2 + 2( \sqrt{5} - \sqrt{5})^2 \\ \\ \\ 2( 3 + 3) + 2 * 0 \\ \\ 2 * 6 => 12[$

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b)
$\dfrac{4}{a^3 - 1} - \dfrac{4}{a^3 + 1}$

mmc = $a^3 - 1 * a^3 + 1$

$\dfrac{4 *(a^2 + 1) - 4 * (a^3 - 1)}{a^3 - 1 * a^3 + 1} \\ \\ \\ \dfrac{4a^3 + 4} - 4a^3 + 4{a^6 - 1} \\ \\ \\ => \dfrac{8}{a^6 - 1}$