Lời giải:
\(x=\frac{2-\sqrt{3}}{2}=\frac{4-2\sqrt{3}}{4}=\frac{3+1-2\sqrt{3}}{4}=\frac{(\sqrt{3}-1)^2}{2^2}\)
\(\Rightarrow \sqrt{x}=\frac{\sqrt{3}-1}{2}\)
\(P=\frac{4\sqrt{x}}{(\sqrt{x}+1)^2}=\frac{2(\sqrt{3}-1)}{(\frac{\sqrt{3}-1}{2}+1)^2}=\frac{8(\sqrt{3}-1)}{(\sqrt{3}+1)^2}=-20+12\sqrt{3}\)