\(a,A=\frac{15\sqrt{x}-11}{x+2\sqrt{x}-3}-\frac{3\sqrt{x}-2}{1-\sqrt{x}}-\frac{3}{\sqrt{x}+3}\)
\(\Leftrightarrow\frac{-\left(15\sqrt{x}-11\right)-\left(3\sqrt{x}-2\right)\left(\sqrt{x}+3\right)-3\left(1-\sqrt{x}\right)}{-x-2\sqrt{x}+3}\)
\(\Leftrightarrow\frac{-15\sqrt{x}+11-3x-9\sqrt{x}+2\sqrt{x}+6-3+3\sqrt{x}}{-x-2\sqrt{x}+3}\)
\(\Leftrightarrow\frac{19\sqrt{x}+3x-14}{x+2\sqrt{x}-3}\)
\(b,\) Xét \(\frac{19\sqrt{x}+3x-14}{x+2\sqrt{x}-3}\) phân tử \(13\sqrt{x}-5\)
Vậy để biểu thức trên nguyên thì \(13\sqrt{x}-5=0\)
\(\Leftrightarrow x=\left(\frac{5}{13}\right)^2\)
Vậy .......................
~~~~~~~~~ Học Tốt ~~~~~~~~~