a: \(B=\dfrac{x+1-2\sqrt{x}}{x-1}=\dfrac{\left(\sqrt{x}-1\right)^2}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}=\dfrac{\sqrt{x}-1}{\sqrt{x}+1}\)
\(C=\dfrac{x-1}{\sqrt{x}\left(\sqrt{x}+1\right)}=\dfrac{\sqrt{x}-1}{\sqrt{x}}\)
b: B*C=1/3
=>\(\dfrac{\left(\sqrt{x}-1\right)^2}{\sqrt{x}\left(\sqrt{x}+1\right)}=\dfrac{1}{3}\)
=>\(3\left(x-2\sqrt{x}+1\right)=x+\sqrt{x}\)
=>\(2x-7\sqrt{x}+3=0\)
=>\(\left(\sqrt{x}-3\right)\left(2\sqrt{x}-1\right)=0\)
=>x=9 hoặc x=1/2
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