1: ĐKXĐ: x>=0; x<>1
\(A=\dfrac{3x\sqrt{x}+8x-5+\sqrt{x}+2+\sqrt{x}-1-2x-2\sqrt{x}+4}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}:\left(\sqrt{x}+1\right)\)
\(=\dfrac{3x\sqrt{x}+6x}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}\cdot\dfrac{1}{\sqrt{x}+1}\)
\(=\dfrac{3x}{x-1}\)
2: Để A là số nguyên thì \(3x-3+3⋮x-1\)
\(\Leftrightarrow x-1\in\left\{1;-1;3;-3\right\}\)
hay \(x\in\left\{2;0;4\right\}\)
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