Answer
$x=1$
Work Step by Step
$\sqrt{3-2\sqrt{x}}=\sqrt x\\(\sqrt{3-2\sqrt{x}})^2=(\sqrt x)^2\\3-2\sqrt{x}=x\\3-x=2\sqrt{x}\\(3-x)^2=(2\sqrt{x})^2\\9+x^2-6x=4x\\x^2-10x+9=x^2-x-9x+9=x(x-1)-9(x-1)=(x-1)(x-9)=0$
Thus $x=1$ or $x=9$ but the equation is undefined for the latter, thus $x=1$.