Svolgimento:
$x/sqrt(2)-x^2/(2-sqrt(2))+(x^2-xsqrt(2))/(2+sqrt(2))+2(x^2-2)/sqrt(2)=1/(1-sqrt(2))$
razionalizzando
$xsqrt(2)/2-x^2(2+sqrt(2))/2+(x^2-xsqrt(2))(2-sqrt(2))/2+(2x^2sqrt(2-4sqrt(2))/2)=-1-sqrt(2)$
e riducendo a forma intera
$xsqrt(2)-2x^2-x^2sqrt(2)+2x^2-x^2sqrt(2)-2xsqrt(2)+2x+2x^2sqrt(2)-4sqrt(2)=-2-2sqrt(2)$
e riducendo i termini simili
$2x-xsqrt(2)=-2+2sqrt(2)$
ovvero
$x(2-sqrt(2))=2(sqrt(2)-1)$
da cui
$x=2(sqrt(2)-1)/(2-sqrt(2))$
e razionalizzando
$x=2(sqrt(2)-1)(2+sqrt(2))/2$
cioe’
$x=2(2sqrt(2)+2-2-sqrt(2))/2=2sqrt(2)/2=sqrt(2)$.

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