Question

giúp mik với ạ

Answer 1

a: \(A=\dfrac{2x+1-x-\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}:\dfrac{x+\sqrt{x}+1-x+2}{x+\sqrt{x}+1}\)

\(=\dfrac{\left(\sqrt{x}-1\right)\cdot\sqrt{x}}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}\cdot\dfrac{x+\sqrt{x}+1}{\sqrt{x}+3}=\dfrac{\sqrt{x}}{\sqrt{x}+3}\)

b: Khi x=(4-2căn 3)/4 thì \(A=\dfrac{\sqrt{3}-1}{2}:\dfrac{\sqrt{3}-1+6}{2}=\dfrac{\sqrt{3}-1}{\sqrt{3}+1}\)

c: A là số nguyên

=>căn x+3-3 chia hết cho căn x+3

=>căn x+3=3

=>x=0