a: Khi x=7-4căn 3 thì \(Q=\dfrac{2-\sqrt{3}+1}{2-\sqrt{3}+2}=\dfrac{3-\sqrt{3}}{4-\sqrt{3}}=\dfrac{9-\sqrt{3}}{13}\)
b; M=P*Q
\(=\dfrac{\sqrt{x}\left(\sqrt{x}-1\right)+\sqrt{x}+1-2\sqrt{x}}{x-1}\cdot\dfrac{\sqrt{x}+1}{\sqrt{x}+2}\)
\(=\dfrac{x-\sqrt{x}-\sqrt{x}+1}{\sqrt{x}-1}\cdot\dfrac{1}{\sqrt{x}+2}=\dfrac{\sqrt{x}-1}{\sqrt{x}+2}\)
c: M<-1/3
=>M+1/3<0
=>\(\dfrac{\sqrt{x}-1}{\sqrt{x}+2}+\dfrac{1}{3}< 0\)
=>3căn x-3+căn x+2<0
=>4căn x<1
=>0<=x<1/16
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