Rút gọn\(1.A=\left(\frac{2\sqrt{x}}{\sqrt{x} 3} \frac{\sqrt{x}}{\sqrt{x}-3}-\frac{3x 3}{x-9}\right):\left(\frac{2\sqrt{x}-2}{\sqrt{x}-3}-1\right)\)\(2.B=\left(\frac{\sqrt{a} 1}{\sqrt{ab} 1} \frac{\sqr...

Tìm ĐKXĐ và rút gọn biểu...

0

NN

Nguyễn Ngọc Tú Uyên

17 tháng 10 2016

1

NL

Nguyễn Lê Phước Thịnh

5 tháng 2 2022

a: \(A=\dfrac{\left(\sqrt{a}-\sqrt{b}\right)^2}{\sqrt{a}-\sqrt{b}}-\dfrac{\sqrt{ab}\left(\sqrt{a}+\sqrt{b}\right)}{\sqrt{ab}}\)

\(=\sqrt{a}-\sqrt{b}-\sqrt{a}-\sqrt{b}=-2\sqrt{b}\)

b: \(B=\dfrac{2\sqrt{x}-x-x-\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}\cdot\dfrac{x+\sqrt{x}+1}{x-1}\)

\(=\dfrac{-2x+\sqrt{x}-1}{\sqrt{x}-1}\cdot\dfrac{1}{x-1}\)

c: \(C=\dfrac{x-9-x+3\sqrt{x}}{x-9}:\left(\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+\dfrac{\sqrt{x}-2}{\sqrt{x}+3}+\dfrac{x-9}{x+\sqrt{x}-6}\right)\)

\(=\dfrac{3\left(\sqrt{x}-3\right)}{x-9}:\dfrac{9-x+x-4\sqrt{x}+4+x-9}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-2\right)}\)

\(=\dfrac{3}{\sqrt{x}+3}\cdot\dfrac{\left(\sqrt{x}+3\right)\left(\sqrt{x}-2\right)}{x-4\sqrt{x}+4}\)

\(=\dfrac{3}{\sqrt{x}-2}\)

Bài 1:Rút gọn\(a,\frac{2}{\sqrt{3}-1}-\frac{2}{\sqrt{3}+1}\)\(b,\frac{2}{5-\sqrt{3}}+\frac{3}{\sqrt{6}+\sqrt{3}}\)\(c,\left(1+\frac{a+\sqrt{a}}{1+\sqrt{a}}\right)\times\left(1-\frac{a-\sqrt{a}}{\sqrt{a}-1}\right)+a\left(a\ne1;a\ge0\right)\)Bài 2: Rút gọn biểu...

NL

nguyen le duy hung

11 tháng 7 2018

1

KT

Không Tên

11 tháng 7 2018

Bài 1:

a) \(\frac{2}{\sqrt{3}-1}-\frac{2}{\sqrt{3}+1}\)

\(=\frac{2\left(\sqrt{3}+1\right)}{\left(\sqrt{3}-1\right)\left(\sqrt{3}+1\right)}-\frac{2\left(\sqrt{3}-1\right)}{\left(\sqrt{3}+1\right)\left(\sqrt{3}-1\right)}\)

\(=\frac{2\left(\sqrt{3}+1\right)}{2}-\frac{2\left(\sqrt{3}-1\right)}{2}\)

\(=\sqrt{3}+1-\left(\sqrt{3}-1\right)=2\)

b) \(\frac{2}{5-\sqrt{3}}+\frac{3}{\sqrt{6}+\sqrt{3}}\)

\(=\frac{2\left(5+\sqrt{3}\right)}{\left(5-\sqrt{3}\right)\left(5+\sqrt{3}\right)}+\frac{3\left(\sqrt{6}-\sqrt{3}\right)}{\left(\sqrt{6}+\sqrt{3}\right)\left(\sqrt{6}-\sqrt{3}\right)}\)

\(=\frac{2\left(5+\sqrt{3}\right)}{2}+\frac{3\left(\sqrt{6}-\sqrt{3}\right)}{3}\)

\(=5+\sqrt{3}+\sqrt{6}-\sqrt{3}=5+\sqrt{6}\)

c) ĐK: \(a\ge0;a\ne1\)

\(\left(1+\frac{a+\sqrt{a}}{1+\sqrt{a}}\right).\left(1-\frac{a-\sqrt{a}}{\sqrt{a}-1}\right)+a\)

\(=\left(1+\frac{\sqrt{a}\left(\sqrt{a}+1\right)}{1+\sqrt{a}}\right).\left(1-\frac{\sqrt{a}\left(\sqrt{a}-1\right)}{\sqrt{a}-1}\right)+a\)

\(=\left(1+\sqrt{a}\right)\left(1-\sqrt{a}\right)+a\)

\(=1-a+a=1\)

LT

Lê Thị Uyển Nhi

9 tháng 10 2017

Rút gọn A khi A = \(\left[\frac{2\sqrt{x}}{\sqrt{x}+3}+\frac{\sqrt{x}}{\sqrt{x}-3}-\frac{3x+3}{x-9}\right]:\left[\frac{2\sqrt{x}-2}{\sqrt{x}-3}-1\right]\)

0

SY

See you again

8 tháng 7 2019

Rút gọn \(P=\left(\frac{2\sqrt{x}}{\sqrt{x}+3}+\frac{\sqrt{x}}{\sqrt{x}+3}-\frac{3x+3}{x-9}\right):\left(\frac{2\sqrt{x}-2}{\sqrt{x}-3}-1\right)\)

2

NH

Nguyễn Hữu Trí

8 tháng 7 2019

Bạn xem lại có ghi sai đề ko vậy

SY

See you again

8 tháng 7 2019

đề không sai đâu bạn

Rút gọn biểu thức: a) \(A=\left(\frac{3x-3\sqrt{x}-3}{x+\sqrt{x}-2}+\frac{1}{\sqrt{x}-1}-\frac{1}{\sqrt{x}+2}\right):\frac{1}{\sqrt{x}+2}\left(x\ge0,x\ne1\right)\) b) \(B=\frac{x\sqrt{x}-3}{x-2\sqrt{x}-3}-\frac{2\left(\sqrt{x-3}\right)}{\sqrt{x}+1}+\frac{\sqrt{x}+3}{3-\sqrt{x}}\left(x0,x\ne9\right)\) c)...

NC

Nguyễn Châu Mỹ Linh

31 tháng 7 2020

0

TT

Trịnh Trọng Khánh

22 tháng 10 2016

Bài 1

C=\(\left(\frac{2\sqrt{x}}{\sqrt{x}+3}+\frac{\sqrt{x}}{\sqrt{x}-3}+\frac{3x+3}{9-x}\right):\left(\frac{\sqrt{x}-1}{\sqrt{x}-3}-\frac{1}{2}\right)\)

a,Rút gọn

b,tìm x để C=\(\frac{1}{2}\)

1

PT

Phạm Thị Huệ

25 tháng 10 2016

\(C=\left(\frac{2\sqrt{x}}{\sqrt{x}-3}+\frac{\sqrt{x}}{\sqrt{x}-3}+\frac{3x+3}{9-x}\right):\left(\frac{\sqrt{x}-1}{\sqrt{x}-3}-\frac{1}{2}\right)\) ĐK \(x\ge0;x\ne9\)

\(C=\left(\frac{2\sqrt{x}\left(\sqrt{x}-3\right)}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}+\frac{\sqrt{x}\left(\sqrt{x}+3\right)}{\left(\sqrt{x}-3\right)\left(\sqrt{x+3}\right)}-\frac{3x+3}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}\right):\left(\frac{2\left(\sqrt{x}-1\right)}{2\left(\sqrt{x}-3\right)}-\frac{1\left(\sqrt{x}-3\right)}{2\left(\sqrt{x}-3\right)}\right)\)

\(C=\frac{2x-6\sqrt{x}+x+3\sqrt{x}-3x+3}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}:\left(\frac{2\sqrt{x}-2-\sqrt{x}+3}{2\left(\sqrt{x}-3\right)}\right)\)

\(C=\frac{-3\sqrt{x}+3}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}:\frac{\sqrt{x}+1}{2\left(\sqrt{x}-3\right)}\)

\(C=\frac{-3\left(\sqrt{x}+1\right)}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)}\) x \(\frac{2\left(\sqrt{x}-3\right)}{\sqrt{x}+1}\)

\(C=\frac{-6}{\sqrt{x}+3}\)

b: ta có \(C=\frac{-6}{\sqrt{x}+3}\) mà \(C=\frac{1}{2}\)

\(\frac{-6}{\sqrt{x}+3}=\frac{1}{2}\)

\(-12=\sqrt{x}+3\)

\(\sqrt{x}=-15\)(Loại)

=> x không có giá trị nào để C=\(\frac{1}{2}\)