1. Cho A=\frac{2\sqrt{x}-9}{x-5\sqrt{x}+6} - \frac{\sqrt{x}+3}{\sqrt{x}-2} - \frac{2\sqrt{x}+1}{3-\sqrt{x}}
a) Rút gọn A
b) Tìm C khi x=\frac{1}{9}
c) Tìm x\epsilon Z để A\epsilon Z
2. Cho P=\frac{x^2-\sqrt{x}}{x+\sqrt{x}+1} - \frac{2x+\sqrt{x}}{\sqrt{x}} + \frac{2(x-1)}{\sqrt{x}-1}
a) Rút gọn...