Question

!!!!!E urgent!!!!dau coroana!!!!

Answer 1

$x = \frac{1}{ \sqrt{2} - 1 } + \frac{1}{ \sqrt{2} + 1} = \frac{ \sqrt{2} + 1 + ( \sqrt{2 } - 1)}{( \sqrt{2} + 1)( \sqrt{2} - 1) }$


$x = \frac{ \sqrt{2} + 1 + \sqrt{2} - 1 }{ { \sqrt{2} }^{2} - 1} = \frac{2 \sqrt{2} }{2 - 1} = 2 \sqrt{2}$


$y = \sqrt{2} \times ( \sqrt{2} + \frac{1}{ \sqrt{2} } )$


$y = \sqrt{2} \times ( \frac{ \sqrt{2} \times \sqrt{2} + 1}{ \sqrt{2} } )$

$y = \sqrt{2} \times \frac{3}{ \sqrt{2} }$


$y = 3$

a)

$x \times ( \sqrt{8} - \sqrt{2}) = 4$

$x \times (2 \sqrt{2} - \sqrt{2} ) = 4$

$2 \sqrt{2} \times \sqrt{2} = 2 \times 2 = 4$

b)

${x}^{2} - y = {(2 \sqrt{2}) }^{2} - 3$

$= {2}^{2} \times { \sqrt{2} }^{2} - 3$
$= 4 \times 2 - 3$

$= 5$