Question

câu 2 mn ơi mai mk phải hk r

Answer 1

Câu 2: 

\(B=\left(\dfrac{\sqrt{x}\left(x+\sqrt{x}+1\right)}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}+\dfrac{\sqrt{x}+3}{\sqrt{x}-1}\right)\cdot\dfrac{x-1}{2x+2\sqrt{x}-\sqrt{x}-1}\)

\(=\left(\dfrac{\sqrt{x}+\sqrt{x}+3}{\left(\sqrt{x}-1\right)}\right)\cdot\dfrac{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}{\left(\sqrt{x}+1\right)\left(2\sqrt{x}-1\right)}\)

\(=\dfrac{2\sqrt{x}+3}{2\sqrt{x}-1}\)

Để B<0 thì \(2\sqrt{x}-1< 0\)

=>\(2\sqrt{x}< 1\)

=>0<x<1/4