\(A=\frac{x\sqrt{x}+1}{x-1}-\frac{x-1}{\sqrt{x}+1}\)
\(A=\frac{x\sqrt{x}+1}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}-\frac{\left(x-1\right)\left(\sqrt{x}-1\right)}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\)
\(A=\frac{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}-\frac{\left(x-1\right)\left(\sqrt{x}-1\right)}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\)
\(A=\frac{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)-\left(x-1\right)\left(\sqrt{x}-1\right)}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\)
\(A=\frac{\left(x-\sqrt{x}+1\right)-\left(\sqrt{x}-1\right)^2}{\left(\sqrt{x}-1\right)}\)
\(A=\frac{\sqrt{x}}{\left(\sqrt{x}-1\right)}\)
b)Khi \(x=\frac{9}{4}\)
\(\Rightarrow\frac{\sqrt{\frac{9}{4}}}{\sqrt{\frac{9}{4}}-1}=3\)
c)\(A=\frac{\sqrt{x}}{\left(\sqrt{x}-1\right)}< 1\)
\(\Leftrightarrow\sqrt{x}< \sqrt{x}-1\)(Voly)
=>ko có giá trị nào