Câu 1: \(M=\sqrt{\left(1-\sqrt3\right)^2}+\sqrt[3]{\left(1-\sqrt3\right)^3}\)
\(=\sqrt3-1+1-\sqrt3\)
=0
=>Chọn D
Câu 2: \(Q=\frac{x-1}{x+3\sqrt{x}+2}\)
\(=\frac{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}{\left(\sqrt{x}+1\right)\left(\sqrt{x}+2\right)}=\frac{\sqrt{x}-1}{\sqrt{x}+2}\)
=>CHọn C
câu 3: A
Câu 4: \(K=\frac{\sqrt{x}-3}{x-9}-\frac{\sqrt{x}-2}{\sqrt{x}+3}\)
\(=\frac{\sqrt{x}-3}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}-\frac{\sqrt{x}-2}{\sqrt{x}+3}\)
\(=\frac{1}{\sqrt{x}+3}-\frac{\sqrt{x}-2}{\sqrt{x}+3}=\frac{3-\sqrt{x}}{\sqrt{x}+3}\)
=>Chọn B
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