\(A=\dfrac{\sqrt{x}}{\sqrt{x}-2}+\dfrac{\sqrt{x}-1}{\sqrt{x}+2}+\dfrac{\sqrt{x}-10}{x-4}\left(x>=0;x\ne4\right)\\ =\dfrac{\sqrt{x}\left(\sqrt{x}+2\right)+\left(\sqrt{x}-1\right)\left(\sqrt{x}-2\right)+\sqrt{x}-10}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\\ =\dfrac{x+2\sqrt{x}+x-3\sqrt{x}+2+\sqrt{x}-10}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\\ =\dfrac{2x-8}{x-4}\\ =\dfrac{2\left(x-4\right)}{x-4}=2\)
Đk: `x >=0, x ne 4`.
`A = (sqrt x (sqrt x + 2) + (sqrtx - 1)(sqrt x - 2) + sqrt x - 10)/(x-4)`
`= (x + 2 sqrt x + x - 3sqrt x + 2 + sqrt x - 10)/(x-4)`
`= (2x - 8)/(x - 4)`
`= 2(x-4)/(x-4)`
`=2`
