tính(rút gọn)

a,\(\left(x+3-\frac{1}{x+3}\right)\left(x+\frac{3}{x+4}\right)\)

b,\(\left(2x-4-\frac{x-12}{3x+4}\right)\left(3x-2-\frac{10}{2x+1}\right)\)

c,\(\left(2x-8-\frac{x+10}{3x+1}\right)\left(x-6-\frac{x-6}{3x+2}\right)\)

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

B1: Rút gọn A=\(\left(\frac{x}{x-1}-\frac{1}{x^2}\right):\left(\frac{1}{x+1}+\frac{2}{x^2-1}\right)\)

B2: Rút gọn A=\(\left(\frac{x-y}{x+y}-\frac{x+y}{x-y}\right):\frac{-4y^2}{x-y}\)

cho biểu thức \(A=\left(\frac{x}{x^2+4}+\frac{2}{2-x}+\frac{1}{x+2}\right):\left(\left(x-2\right)+\frac{10-x^2}{x+2}\right)\)

rút gọn A

Bài 1 rút gọn biểu thức 

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

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

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

a) \(\left(\frac{4}{x^3-9x}+\frac{1}{x+3}\right):\left(\frac{x-3}{x^2+3x}-\frac{x}{3x+9}\right)\)

b) \(\left(\frac{2}{x-2}-\frac{2}{x+2}\right).\frac{x^2+4x+4}{8}\)

c) \(\left(\frac{3x}{1-3x}+\frac{2x}{3x+1}\right):\frac{6x^2+10x}{1-6x+9x^2}\)

\(\frac{\left(x+\frac{1}{x}\right)^4-\left(x^4+\frac{1}{x^4}\right)-2}{\left(x+\frac{1}{x}\right)^4+x^2+\frac{1}{x^2}}\cdot\frac{x^4+1999x^2+1}{2x^2}\)

a,Rút gọn bt

b,tính giá trị của bt biết \(x^2-4x+1=0\)

Rút gọn biểu thức:
\(\frac{1}{2}x^2.\left(6x-3\right)-x\left(x^2+\frac{1}{2}\right)+\frac{1}{2}\left(x+4\right)\)