[tex]\\x=1-\sqrt2*x \\x+x\sqrt2=1 \\x(1+\sqrt2)=1/:(1+\sqrt2) \\x=\frac{1}{1+\sqrt2}*\frac{1-\sqrt2}{1-\sqrt2} \\x=\frac{1-\sqrt2}{1-2} \\x=\sqrt2-1[/tex]
x = 1 - √2 x
x + 2√x = 1
x(1+√2) = 1 /(1+√2)
x = 1/(1+√2) * (1-√2)/(1-√2) = (1-√2)/(1-2) = -(1-√2) = √2 - 1
