Question

rút gọn

\(C=\left(\dfrac{\sqrt{a}}{\sqrt{a}-1}-\dfrac{\sqrt{a}}{a-\sqrt{a}}\right):\dfrac{\sqrt{a}+1}{a-1}\)

Answer 1

\(C=\dfrac{a-\sqrt{a}}{\sqrt{a}\left(\sqrt{a}-1\right)}\cdot\dfrac{a-1}{\sqrt{a}+1}=\dfrac{\sqrt{a}}{\sqrt{a}}\cdot\left(\sqrt{a}-1\right)=\sqrt{a}-1\)

Answer 2

Với `a > 0,a \ne 1` có:

`C=(\sqrt{a}/[\sqrt{a}-1]-\sqrt{a}/[a-\sqrt{a}]):[\sqrt{a}+1]/[a-1]`

`C=[a-\sqrt{a}]/[\sqrt{a}(\sqrt{a}-1)].[(\sqrt{a}-1)(\sqrt{a}+1)]/[\sqrt{a}+1]`

`C=[\sqrt{a}(\sqrt{a}-1)]/[\sqrt{a}(\sqrt{a}-1)].[\sqrt{a}-1)(\sqrt{a}+1)]/[\sqrt{a}+1]`

`C=\sqrt{a}-1`