RÚT GỌN CÁC BIỂU THỨC SAU:
21) \(A = \left(\dfrac{x\sqrt{x} + 1}{x - 1} - \dfrac{x - 1}{\sqrt{x} - 1}\right) : \left(\sqrt{x} + \dfrac{\sqrt{x}}{\sqrt{x} - 1}\right) \)
22) \(A = \left(\dfrac{x}{\sqrt{x} - 1} - \sqrt{x}\right) : \left(\dfrac{\sqrt{x} + 1}{\sqrt{x}} - \dfrac{1}{1 - \sqrt{x}} + \dfrac{2 - x}{x - \sqrt{x}}\right)\)
23) \(A = \left(\dfrac{\sqrt{x} - 4}{x - 2\sqrt{x}} - \dfrac{3}{2 - \sqrt{x}}\right) : \left(\dfrac{\sqrt{x} + 2}{\sqrt{x}} - \dfrac{\sqrt{x}}{\sqrt{x} - 2}\right)\)
24) \(A = \left(\dfrac{2x + 1}{x\sqrt{x} - 1} + \dfrac{1}{1 - \sqrt{x}}\right) : \left(1 - \dfrac{x - 2}{x + \sqrt{x} + 1}\right)\)
25) \(A = 1 : \left(\dfrac{x + 2\sqrt{x} - 2}{x\sqrt{x} + 1} - \dfrac{\sqrt{x} -1}{x - \sqrt{x} + 1} + \dfrac{1}{\sqrt{x} + 1}\right)\)
26) \(A = \left(\dfrac{\sqrt{x}}{\sqrt{x} + 2} - \dfrac{3}{2 - \sqrt{x}} + \dfrac{3\sqrt{x} - 2}{x - 2}\right) : \left(\dfrac{\sqrt{x} + 3}{\sqrt{x} - 2} + \dfrac{2\sqrt{x}}{2\sqrt{x} - x}\right)\)
27) \(P = \left(\dfrac{4\sqrt{x}}{2 + \sqrt{x}} + \dfrac{8}{4 - x}\right) : \left(\dfrac{\sqrt{x} - 1}{x - 2\sqrt{x}} - \dfrac{2}{\sqrt{x}}\right)\)