a) [tex] (\frac{1}{ \sqrt{2}-1 }+ \frac{1}{ \sqrt{2}+1 } )* ( \sqrt{8}- \sqrt{2})=4
[/tex]
luam prima paranteza si rationalizam numitorul(cu conjugata fiecareia) si vom obtine:
[tex] \sqrt{2} +1+ \sqrt{2} -1=2 \sqrt{2} [/tex]
Dupa care facem inmultirea: [tex]2 \sqrt{2} ( \sqrt{8} - \sqrt{2} )=2 \sqrt{16} -2 \sqrt{4}= 4 ADEVARAT[/tex]
b)y=[tex] \sqrt{2} ( \sqrt{2} + \frac{1}{ \sqrt{2} } )= \sqrt{4} +1=2
[/tex]
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=> [tex] x^{2} -y=8-2=6[/tex]
