Question

cứu mik vs

Answer 1

Đk: `x >=0, x ne 0, 4.`

`((sqrt x)/(2 + sqrt x) + (x+4)/(4 - x) ) : x/(x - 2sqrt x)`

`= (sqrtx(2 - sqrt x))/((2 + sqrt x)(2 - sqrt x)) + (x+4)/(4-x)) : x/(x- 2 sqrt x)`

`= ((2 sqrt x - x)/(4 - x) + (x+4)/(4-x) ) : x/(sqrtx(sqrtx-2))`.

`= (2(sqrt x + 2))/((2+sqrtx)(2-sqrtx)) : x/(sqrtx(sqrtx-2))`.`

= 2/(2-sqrtx) : sqrtx/(sqrtx-2)`

`= -2/sqrt x = -(2sqrtx)/x`.

Answer 2

\(=\dfrac{2\sqrt{x}-x+x+4}{4-x}\cdot\dfrac{x-2\sqrt{x}}{x}\)

\(=\dfrac{2\left(\sqrt{x}+2\right)\cdot\sqrt{x}\left(\sqrt{x}-2\right)}{x\left(4-x\right)}=-\dfrac{2}{\sqrt{x}}\)