a: \(B=\dfrac{x+3+\sqrt{x}-3}{x-9}\cdot\dfrac{\sqrt{x}-3}{\sqrt{x}}=\dfrac{x+\sqrt{x}}{\sqrt{x}+3}\cdot\dfrac{1}{\sqrt{x}}=\dfrac{\sqrt{x}+1}{\sqrt{x}+3}\)
b: \(B-\dfrac{1}{3}=\dfrac{\sqrt{x}+1}{\sqrt{x}+3}-\dfrac{1}{3}=\dfrac{3\sqrt{x}+3-\sqrt{x}-3}{\sqrt{x}+3}>0\)
=>B>1/3
40. B=\(\left(\dfrac{\sqrt{x}}{\sqrt{x}+3}+\dfrac{2\sqrt{x}}{\sqrt{x}-3}-\dfrac{3x+9}{x-9}\right).\left(\dfrac{\sqrt{x}-2}{3}+1\right)\)
b. Rút gọn B
Rút gọn
\(\dfrac{6}{\sqrt{5}+1}+\sqrt{\dfrac{2}{3-\sqrt{5}}}-\dfrac{10}{\sqrt{5}}\)
B1. Với \(x\ge0,x\ne4.Chobiểuthức\)
\(A=\dfrac{x-9}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-2\right)}-\dfrac{1}{2-\sqrt{x}}-\dfrac{\sqrt{x}}{\sqrt{x}+3}\)
\(B=\dfrac{1}{x\sqrt{x}+27}\)
a, tính giá trị biểu thức khi B= 1/4
b, Rút gọn A
c, Tìm giá trị của x để A>1/2
d, Với C= B : A. Tìm GTLN C
\(\left(\dfrac{x+3\sqrt{x}-2}{x-9}-\dfrac{1}{\sqrt{x}+3}\right)\)\(\dfrac{\sqrt{x}-3}{\sqrt{x}+1}\)
RÚT GỌN GIÚP MÌNH VỚI
Bài 1: Rút gọn biểu thức dạng chữ:
3) \(A=\left(\dfrac{\sqrt{x}}{\sqrt{x}+3}.\dfrac{3}{\sqrt{x}-3}\right).\dfrac{\sqrt{x}+3}{x+9}\) với x\(\ge0\), x ≠9
4) \(P=\dfrac{x-2}{x+2\sqrt{x}}-\dfrac{1}{\sqrt{x}}+\dfrac{1}{\sqrt{x}+2}\) với x ≥ 0
5) \(B=\left(1+\dfrac{x+\sqrt{x}}{\sqrt{x}+1}\right).\left(1-\dfrac{x-\sqrt{x}}{\sqrt{x}-1}\right)\)với x > 0, x ≠ 1
\(\left(\dfrac{x+2\sqrt{x}+7}{x-9}+\dfrac{\sqrt{x}-1}{3-\sqrt{x}}\right):\left(\dfrac{1}{\sqrt{x}+3}-\dfrac{1}{\sqrt{x}-1}\right)\) RÚT GỌN
A= \(\dfrac{3}{\sqrt{7}-2}\) + \(\sqrt{\left(\sqrt{7}-3\right)}^2\)
B= \(\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{\sqrt{x}}{x-\sqrt{x}}\right)\):\(\left(\dfrac{\sqrt{x}+1}{x-1}\right)\)
Rút gọn A,B
Rút gọn biểu thức:P=\(\left(\dfrac{3\sqrt{x}}{\sqrt{x}-3}+\dfrac{4\sqrt{x}}{\sqrt{x}+3}+\dfrac{7x-3}{9-x}\right):\left(\dfrac{2\sqrt{x}-4}{\sqrt{x}-3}-1\right)\)
Rút gọn biểu thức
\(\left(\dfrac{1}{\sqrt{x}+3}+\dfrac{1}{\sqrt{x}-3}\right).\dfrac{x-6\sqrt{x}+9}{\sqrt{x}}\)
\(\dfrac{x}{\sqrt{x}+1}+\dfrac{2x+\sqrt{x}}{x+\sqrt{x}}\)
28. A=\(\left(\dfrac{x-3\sqrt{x}}{x-9}-1\right):\left(\dfrac{9-x}{x+\sqrt{x}-6}+\dfrac{\sqrt{x}-3}{\sqrt{x}-2}-\dfrac{\sqrt{x}-2}{\sqrt{x}+3}\right)\)
a. rút gọn A
b. tính A với x = \(7-4\sqrt{3}\)
c. tìm x khi A=3
Rút gọn biểu thức sau
A=\(\dfrac{1}{x-1}\sqrt{75\left(x-1\right)^3}\left(x>1\right)
\)
B=\(5\sqrt{4x}-3\sqrt{\dfrac{100x}{9}}-\dfrac{4}{x}\sqrt{\dfrac{x^3}{4}}\left(x>0\right)
\)
C=\(x-4+\sqrt{16-8x+x^2}\left(x>4\right)\)
Help me
