K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

21 tháng 12 2020

Mk sai từ dòng 3 nhá -- 

\(=\left(x^2-1\right)\left(\frac{2-\left(x^2-1\right)}{\left(x-1\right)\left(x+1\right)}\right)\)

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

21 tháng 12 2020

\(\left(x^2-1\right)\left(\frac{1}{x-1}-\frac{1}{x+1}-1\right)\)

\(=\left(x^2-1\right)\left(\frac{x+1}{\left(x-1\right)\left(x+1\right)}-\frac{x-1}{\left(x+1\right)\left(x-1\right)}-\frac{\left(x+1\right)\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}\right)\)

\(=\left(x^2-1\right)\left(\frac{-\left(x^2-1\right)}{\left(x-1\right)\left(x+1\right)}\right)\)

\(=\frac{-\left(x-1\right)^2\left(x+1\right)^2}{\left(x-1\right)\left(x+1\right)}=-\left(x-1\right)\left(x+1\right)=-x^2+1\)

\(\Rightarrow\)\(\left(\frac{1}{2}\right)^{2x-1}=\)\(\left(\frac{1}{2}\right)^3\)

\(\Rightarrow2x-1=3\)

     \(2x=3+1\)

  \(2x=4\)

 \(x=4:2=2\)

17 tháng 8 2021

( 1/2 ) 2x -1= ( 1/2 ) 3 

2x - 1 =3 

2x = 3+1

2x=4

x= 4:2 = 2

13 tháng 2 2020

Mình thử nha :33

ĐKXĐ : \(x\ne-3,x\ne-26,x\ne-6,x\ne1\)

Ta có :

\(A=\left[\frac{3}{2}-\left(\frac{x^4\left(x^2+1\right)-x^4-1}{x^2+1}\right)\cdot\frac{x^3-4x^2+\left(x-4\right)}{x^6\left(x+6\right)-\left(x+6\right)}\right]:\frac{\left(x+3\right)\left(x+26\right)}{3\left(x-2\right)\left(x+6\right)}\)

\(=\left[\frac{3}{2}-\left(\frac{x^6-1}{x^2+1}\right)\cdot\frac{\left(x-4\right)\left(x^2+1\right)}{\left(x+6\right)\left(x^6-1\right)}\right]\cdot\frac{3\left(x-2\right)\left(x+6\right)}{\left(x+3\right)\left(x+26\right)}\)

\(=\left[\frac{3}{2}-\frac{x-4}{x+6}\right]\cdot\frac{3\left(x-2\right)\left(x+6\right)}{\left(x+3\right)\left(x+26\right)}\)

\(=\frac{x+26}{2\left(x+6\right)}\cdot\frac{3\left(x-2\right)\left(x+6\right)}{\left(x+3\right)\left(x+26\right)}\)

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

Vậy : \(A=\frac{3\left(x-2\right)}{2\left(x+3\right)}\left(x\ne-3,x\ne-26,x\ne-6,x\ne1\right)\)

28 tháng 11 2016

\(A=\left(\frac{x+1}{x-1}-\frac{x-1}{x+1}+\frac{x^2-4x-1}{x^2-1}\right):\left(\frac{x+2006}{x}\right)\)

\(=\left(\frac{x^2+2x+1-x^2+2x-1+x^2-4x-1}{x^2-1}\right):\left(\frac{x+2006}{x}\right)\)

\(=\frac{x^2-1}{x^2-1}:\frac{x+2006}{x}=\frac{x}{x+2006}\)

DD
29 tháng 7 2021

\(\left(-1\frac{1}{2}\right)\left(-1\frac{1}{3}\right)\left(-1\frac{1}{4}\right)...\left(-1\frac{1}{2003}\right)\left(-1\frac{1}{2004}\right)\)

\(=-\frac{3}{2}.\frac{4}{3}.\frac{5}{4}.....\frac{2004}{2003}.\frac{2005}{2004}\)

\(=-\frac{3.4.5.....2004.2005}{2.3.4.....2003.2004}=\frac{-2005}{2}\)