2 vế suy ra là từ hằng đẳng thức rồi
( x- y)2=( x- y)( x- y)=x( x- y) - y( x- y)=x2- xy- xy+y2=x2- 2xy+y2
( x+y)2=( x+y)( x+y)=x(x+y)+y(x+y)=x2+xy+xy+1=x2+2xy+y2
Còn vế ta có suy ra từ đó.
\(\left(\frac{1}{x+1}-\frac{3}{x^3+1}+\frac{3}{x^2-x+1}\right).\frac{3x^2-3x+3}{\left(x+1\right)\left(x+2\right)}-\frac{2x-2}{x^2+2x}\) thực hiện phép tính
1 . Thực hiện phép tính :
a ) \(\frac{1}{x-1}+\frac{1}{\left(1-x\right)\left(2-x\right)}+\frac{1}{\left(x-2\right)\left(x-3\right)}\)
b ) \(\frac{4-2x+x^2}{2+x}-2-x\)
c ) \(\left(\frac{1}{1+x}+\frac{2x}{1-x^2}\right)\left(\frac{1}{x}-1\right)\)
d ) \(\left(\frac{x+1}{x-1}-\frac{x-1}{x+1}\right):\left(\frac{1}{x+1}-\frac{x}{1-x}+\frac{2}{x^2-1}\right)\)
giúp với câu nào cũng đc ! mk sẽ tick cho 3 cái !!! 
Tính:
\(\frac{1}{x.\left(x+1\right)}+\frac{1}{\left(x+1\right).\left(x+2\right)}+\frac{1}{\left(x+2\right).\left(x+3\right)}+\frac{1}{\left(x+3\right).\left(x+4\right)}+\frac{1}{\left(x+4\right).\left(x+5\right)}+\frac{1}{x+5}\)
Tính tổng: \(A=\frac{x^4-\left(x-1\right)^2}{\left(x^2+1\right)^2-x^2}+\frac{x^2-\left(x^2-1\right)^2}{x^2\left(x+1\right)^2-1}+\frac{x^2\left(x-1\right)^2-1}{x^4-\left(x+1\right)^2}\)
giải jùm vs
Rút gọn Pthức:
A= \(\left(\frac{1}{x+1}-\frac{3}{x^3+1}+\frac{3}{x^2+x+1}\right)\frac{3x^2-3x+3}{\left(x+1\right)\left(x+2\right)}-\frac{2x-2}{x^2+2x}\)
Tinh
\(A=\left(\frac{x}{x+1}+\frac{1}{x-1}\right):\left(\frac{2x+2}{x-1}-\frac{4x}{x^2-1}\right)\)
\(B=\frac{x^2}{x-2}.\left(\frac{x^2+4}{x}-4\right)+5\)
giải phương trình
1. \(\frac{2x+3}{5x-3}\)-\(\frac{3}{4x-6}\)=\(\frac{2}{5}\)
2. \(\frac{1}{x-1}\)-\(\frac{7}{x-2}\)=\(\frac{1}{\left(x-1\right)\left(2-x\right)}\)
3. x+\(\frac{x-1}{x-2}\)=3+\(\frac{1}{x-2}\)
4. \(\frac{x+1}{x-3}\)-\(\frac{1}{x-1}\)=\(\frac{2}{\left(x-1\right)\left(x-3\right)}\)
5. \(\frac{2x-1}{x+1}+\frac{x}{\left(x-1\right)\left(x-2\right)}=\frac{6x-2}{x-2}\)
rút gọn
a) \(\frac{1}{x-y}-\frac{3xy}{x^2-y^2}+\frac{x-y}{x^2+x+y^2}\)
b) \(\frac{1}{x^2+3x+2}+\frac{1}{x^2+4x+4}+\frac{1}{x^2+5x+6}\)
c) \(\frac{4.\left(x+3\right)^2}{\left(3x+5\right)^2-4x^2}-\frac{x^2-25}{9x^2.\left(2x+5\right)^2}-\frac{\left(2x+3\right)^2-x^2}{\left(4x+15\right)^2-x^2}\)
Rút gọn \(\frac{1}{\left(x+y\right)^3}.\left(\frac{1}{x^3}+\frac{1}{y^3}\right)+\frac{3}{\left(x+y\right)^5}.\left(\frac{1}{x^2}+\frac{1}{y^2}\right)+\frac{6}{\left(x+y\right)^5}.\left(\frac{1}{x}+\frac{1}{y}\right)\)