Sửa đề: \(A=2-2\sqrt{x}\)
B-1/2A=0 nên B=1/2A
=>A=2B
\(\Leftrightarrow2-2\sqrt{x}=\dfrac{2\sqrt{x}}{\sqrt{x}-4}\)
\(\Leftrightarrow2\sqrt{x}=\left(\sqrt{x}-4\right)\left(2-2\sqrt{x}\right)\)
\(\Leftrightarrow2\sqrt{x}=2\sqrt{x}-2x-8+4\sqrt{x}\)
=>6 căn x=8
=>căn x=4/3
=>x=16/9