Rút gọn A=căn x-1/căn x + 3 căn x +1/x+ căn x

#andy

\[\begin{array}{l}
A = \frac{{\sqrt {x - 1} }}{{\sqrt x }} + \frac{{3\sqrt {x + 1} }}{{x + \sqrt x }}\,\,DKXD:X > 0\\
 \Leftrightarrow \frac{{\left( {\sqrt x  - 1} \right)\left( {\sqrt x  + 1} \right) + 3\sqrt {x + 1} }}{{\sqrt x \left( {\sqrt x  + 1} \right)}}\\
 \Leftrightarrow \frac{{x - 1 + 3\sqrt x  + 1}}{{\sqrt x \left( {\sqrt x  + 1} \right)}}\\
 \Leftrightarrow \frac{{x + 3\sqrt x }}{{\sqrt x \left( {\sqrt x  + 1} \right)}}\\
 \Leftrightarrow \frac{{\sqrt x \left( {\sqrt x  + 3} \right)}}{{\sqrt x \left( {\sqrt x  + 1} \right)}}\\
 \Leftrightarrow \frac{{\sqrt x  + 3}}{{\sqrt x  + 1}}
\end{array}\]