Question

giúp mình 5 câu này với

Answer 1

a: \(P=\dfrac{\sqrt{x}-2+\sqrt{x}+2+x}{x-4}:\dfrac{\sqrt{x}-2+4}{\sqrt{x}-2}\)

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

\(=\dfrac{\sqrt{x}}{\sqrt{x}+2}\)

b: Khi x=9 thì \(P=\dfrac{3}{3+2}=\dfrac{3}{5}\)

c:Để P=1/3căn x thì \(\dfrac{\sqrt{x}}{\sqrt{x}+2}=\dfrac{1}{3\sqrt{x}}\)

=>3x-căn x-2=0

=>3x-3 căn x+2 căn x-2=0

=>x=1