\(\dfrac{\sqrt{a}-1}{a\sqrt{a}+a+\sqrt{a}}.\left(a^2-\sqrt{a}\right)=\dfrac{\sqrt{a}-1}{\sqrt{a}\left(a+\sqrt{a}+1\right)}.\left[\sqrt{a}\left(\sqrt{a}-1\right)\left(a+a+1\right)\right]\)
\(=\left(\sqrt{a}-1\right)^2\)
Rút gọn:
\(E=\left(1-a^2\right):\left[\left(\dfrac{1-a\sqrt{a}}{1-\sqrt{a}}+\sqrt{a}\right)\cdot\left(\dfrac{1+a\sqrt{a}}{1+\sqrt{a}}-\sqrt{a}\right)\right]\)
Rút gọn biểu thức sau :
A =\(\left(\dfrac{x-2}{x+2\sqrt{x}}+\dfrac{1}{\sqrt{x}+2}\right).\dfrac{\sqrt{x}+1}{\sqrt{x}-1}\)
a/C/m A = \(\dfrac{\sqrt{x}+1}{\sqrt{x}}\)
b/ Tìm cá giá trị của x để 2P = 2\(\sqrt{x}+5\)
\(A=\left(\dfrac{\sqrt{x}+2}{x-5\sqrt{x}+6}-\dfrac{\sqrt{x}+3}{2-\sqrt{x}}-\dfrac{\sqrt{x}+2}{\sqrt{x}-3}\right):\left(2-\dfrac{\sqrt{x}}{\sqrt{x}+1}\right)\)
a) Rút gọn A
b) Cho |x| = 3. Tính A
Rút gọn D = \(\left(\sqrt{a}+\dfrac{b-\sqrt{ab}}{\sqrt{a}+b}\right):\left(\dfrac{a}{\sqrt{ab}+b}+\dfrac{b}{\sqrt{ab}-a}-\dfrac{a+b}{\sqrt{ab}}\right)\)
Rút gọn:
\(D=\left(\sqrt{a}+\dfrac{b-\sqrt{ab}}{\sqrt{a}+b}\right):\left(\dfrac{a}{\sqrt{ab}+b}+\dfrac{b}{\sqrt{ab}-a}-\dfrac{a+b}{\sqrt{ab}}\right)\)
\(A=\left(\dfrac{x-5\sqrt{x}}{x-25}-1\right):\left(\dfrac{25-x}{x+2\sqrt{x}-15}-\dfrac{\sqrt{x}+3}{\sqrt{x}+5}+\dfrac{\sqrt{x}-5}{\sqrt{x}+3}\right)\)
\(B=\left(\dfrac{2+x}{2-x}-\dfrac{4x^2}{x^2-4}-\dfrac{2-x}{x+2}\right):\dfrac{x^2-3x}{2x^2-x^3}\)
a) Rút gọn A & B
b) Tìm x để B > 0
c) Tính B khi \(\left|1-x\right|=0\)
\(B=\left(\dfrac{\sqrt{x}+2}{x-2\sqrt{x}+1}+\dfrac{\sqrt{x}-2}{1-x}\right):\left(\dfrac{x+1}{x-1}-1\right)\)
a) Rút gọn A
b) Tính B với \(\left|2\sqrt{x}-1\right|=3\)
Rút gọn:
\(A=\left(\dfrac{1}{\sqrt{x}-1}+\dfrac{x-\sqrt{x}+1}{x+\sqrt{x}-2}\right):\left(\dfrac{\sqrt{x}+1}{\sqrt{x}+2}-\dfrac{x-\sqrt{x}-4}{x+\sqrt{x}-2}\right)\)
Tìm tập xác định và rút gọn \(A=\dfrac{3\left(\sqrt{ab}-b\right)}{a-b}+\dfrac{\left(\sqrt{a}-\sqrt{b}\right)^3+2a\sqrt{a}+b\sqrt{b}}{a\sqrt{a}+b\sqrt{b}}\)
