($\frac{√x+2}{x+2√x+1}$-$\frac{√x-2}{x-1}$).$\frac{√x-2}{x-1}$ rút gọn hộ mình nha

2 câu trả lời

$(\dfrac{\sqrt[]{x}+2}{x+2\sqrt[]{x}+1}-$ $\dfrac{\sqrt[]{x}-2}{x-1}).$ $\dfrac{\sqrt[]{x}+1}{\sqrt[]{x}}$

$=(\dfrac{\sqrt[]{x}+2}{(\sqrt[]{x}+1)^2}-$ $\dfrac{\sqrt[]{x}-2}{(\sqrt[]{x}-1)(\sqrt[]{x}+1)}).$ $\dfrac{\sqrt[]{x}+1}{\sqrt[]{x}}$

$=\dfrac{(\sqrt[]{x}+2)(\sqrt[]{x}-1)-(\sqrt[]{x}-2)(\sqrt[]{x}+1)}{(\sqrt[]{x}+1)^2.(\sqrt[]{x}-1)}.$ $\dfrac{\sqrt[]{x}+1}{\sqrt[]{x}}$

$\dfrac{x-\sqrt[]{x}+2\sqrt[]{x}-2-(x+\sqrt[]{x}-2\sqrt[]{x}-2)}{(\sqrt[]{x}+1)^2.(\sqrt[]{x}-1)}.$ $\dfrac{\sqrt[]{x}+1}{\sqrt[]{x}}$

$=\dfrac{x+\sqrt[]{x}-2-x+\sqrt[]{x}+2}{(\sqrt[]{x}+1)^2.(\sqrt[]{x}-1)}.$ $\dfrac{\sqrt[]{x}+1}{\sqrt[]{x}}$

$=\dfrac{2\sqrt[]{x}}{(\sqrt[]{x}+1)^2.(\sqrt[]{x}-1)}.$ $\dfrac{\sqrt[]{x}+1}{\sqrt[]{x}}$

$=\dfrac{2(\sqrt[]{x}+1)}{(\sqrt[]{x}+1)^2.(\sqrt[]{x}-1)}$

$=\dfrac{2}{(\sqrt[]{x}-1)(\sqrt[]{x}+1)}$

$=\dfrac{2}{x-1}$

Chúc bạn học tốt !!!!

 

Đáp án + Giải thích các bước giải:

 `((\sqrt{x} + 2)/(x+2\sqrt{x} + 1) - (\sqrt{x} - 2)/(x-1) ) . ((\sqrt{x}+1)/(\sqrt{x}))`

đk : `x` $\neq$ `1`

`=( (\sqrt{x} + 2)/(\sqrt{x}+1)^2  - (\sqrt{x}-2)/((\sqrt{x}+1)(\sqrt{x}-1)) ) . ((\sqrt{x}+1)/(\sqrt{x}))`

`=( (\sqrt{x}+2)(\sqrt{x}-1)-(\sqrt{x}-2)(\sqrt{x}+1))/((\sqrt{x}+1)(x-1)) . ((\sqrt{x}+1)/(\sqrt{x}))`

`=(x+\sqrt{x}-2-(x-\sqrt{x}-2))/((\sqrt{x}+1)(x-1)) . ((\sqrt{x}+1)/(\sqrt{x}))`

`=(x+\sqrt{x}-2-x+\sqrt{x}+2)/((\sqrt{x}+1)(x-1)) . ((\sqrt{x}+1)/(\sqrt{x}))`

`=(2\sqrt{x})/((\sqrt{x}+1)(x-1)) . (\sqrt{x}+1)/\sqrt{x} `

`=(2(\sqrt{x}+1))/((\sqrt{x}+1)(x-1)) `