1: ĐKXĐ: x>=0; \(x\notin\left\{4;1\right\}\)
\(P=\dfrac{x-4\sqrt{x}+3-\left(2x-5\sqrt{x}+2\right)+x-2}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-1\right)}\)
\(=\dfrac{2x-4\sqrt{x}+1-2x+5\sqrt{x}-2}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-1\right)}=\dfrac{1}{\sqrt{x}-2}\)
2: Để P>=2 thì P-2>=0
\(\Leftrightarrow\dfrac{1-2\sqrt{x}+4}{\sqrt{x}-2}>=0\)
\(\Leftrightarrow\dfrac{2\sqrt{x}-5}{\sqrt{x}-2}< =0\)
=>4<x<=25/4
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3, \(\sqrt{x}-2\inƯ\left(1\right)=\left\{\pm1\right\}\)
\(\sqrt{x}-2\) | 1 | -1 |
x | 9 | 1(loại) |
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