`5` Với `x >= 0` có:
`B=[x\sqrt{x}+1]/[x-\sqrt{x}+1]`
`B=[(\sqrt{x})^3+1^3]/[x-\sqrt{x}+1]`
`B=[(\sqrt{x}+1)(x-\sqrt{x}+1)]/[x-\sqrt{x}+1]=\sqrt{x}+1`
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`1)A=2\sqrt{8}-3\sqrt{18}+5\sqrt{32}`
`A=2\sqrt{2^2 .2}-3\sqrt{3^2 .2}+5\sqrt{4^2 .2}`
`A=4\sqrt{2}-9\sqrt{2}+20\sqrt{2}=15\sqrt{2}`
Câu 5:
\(B=\dfrac{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}{x+\sqrt{x}+1}=\sqrt{x}-1\)
Câu 1:
\(A=4\sqrt{2}-9\sqrt{2}+20\sqrt{2}=15\sqrt{2}\)