#### Answer

The answer is: $x=2(3-2\sqrt2)$.

#### Work Step by Step

Given:
$(\sqrt2-1)/(\sqrt2+1)=x/2$
By cross multiplication we get,
$(\sqrt2-1)*2=x*(\sqrt2+1)$
$2(\sqrt2-1)/(\sqrt2+1)=x$
$x=2(\sqrt2-1)/(\sqrt2+1)*(\sqrt2-1)/(\sqrt2-1)$
Multiplying and dividing by $(\sqrt2-1)$:
$x=2(\sqrt2-1)^{2}/(\sqrt2^{2}-1^{2})$
$x=2(2+1-2*\sqrt2*1)/(2-1)$
$x=2(3-2\sqrt2)/(1)$
$x=2(3-2\sqrt2)$.