Question

1.P=\(\left(\dfrac{\sqrt{x}}{\sqrt{x}+2}-\dfrac{\sqrt{x}}{\sqrt{x}-2}+\dfrac{4\sqrt{x}-1}{c-4}\right):\dfrac{1}{\sqrt{c}+2}\)

Tìm x nguyên để P nguyên

Answer 1

c??

Answer 2

Ta có: \(P=\left(\dfrac{\sqrt{x}}{\sqrt{x}+2}-\dfrac{\sqrt{x}}{\sqrt{x}-2}+\dfrac{4\sqrt{x}-1}{x-4}\right):\dfrac{1}{\sqrt{x}+2}\)

\(=\dfrac{x-2\sqrt{x}-x-2\sqrt{x}+4\sqrt{x}-1}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\cdot\dfrac{\sqrt{x}+2}{1}\)

\(=\dfrac{-1}{\sqrt{x}-2}\)

Để P nguyên thì \(\sqrt{x}-2\in\left\{-1;1\right\}\)

\(\Leftrightarrow\sqrt{x}\in\left\{1;3\right\}\)

hay \(x\in\left\{1;9\right\}\)

Answer 3

Mik ko hiểu đề