H24
NT
22 tháng 8 2023 lúc 22:34

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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