Rút gọn A:
\(A=\left(\frac{2}{x+2}-\frac{4}{x^2+4x+4}\right):\left(\frac{2}{x^2-4}+\frac{1}{2-x}\right)\)
Rút gọn biểu thức sau: A=\(\left[\left(x^4-x+\frac{x-3}{x^3+1}\right).\frac{\left(x^3-2x^2+2x-1\right)\left(x+1\right)}{x^9+x^7-3x^2-3}+1-\frac{2\left(x+6\right)}{x^2+1}\right].\frac{4x^2+4x+1}{\left(x+4\right)\left(3-x\right)}\)
Rút gọn A
A=\(\left(\frac{2}{x+2}-\frac{4}{x^2+4x+4}\right):\left(\frac{2}{x^2-4}+\frac{1}{2-x}\right)\)
GIÚP MÌNH VỚI MAI MINH ĐI HỌC RỒI
\(\text{Đ}K\text{X}\text{Đ}:x\ne\pm2\)
Ta có: \(A=\left(\frac{2}{x+2}-\frac{4}{x^2+4x+4}\right)\div\left(\frac{2}{x^2-4}+\frac{1}{2-x}\right)\)
\(=\left(\frac{2x+2-4}{\left(x+2\right)^2}\right):\left(\frac{2-x-2}{\left(x+2\right)\left(x-2\right)}\right)=\frac{2x-2}{\left(x+2\right)^2}\cdot\frac{\left(x+2\right)\left(x-2\right)}{-x}\)
\(=\frac{2\left(x-1\right)\left(x-2\right)}{-x\left(x+2\right)}\)
Cho biểu thức: \(A=\left[\frac{4}{\left(x+2\right)^3}\left(\frac{2}{x}+1\right)+\frac{1}{x^2+4x+4}\left(\frac{4}{x^2}+1\right)\right]:\frac{x^2+1}{x^3-x^2}\)
a) Rút gọn A
b) Tìm giá trị của x để A > 0
c) Tìm giá trị nguyên của x để A nguyên
Bài 1: Rút gọn biểu thức:
a) A = \(\left(\frac{1}{x^2-4x}+\frac{2}{16-x^2}+\frac{4}{4x+16}\right):\frac{1}{4x}\)
\(A=\left(\dfrac{1}{x^2-4x}+\dfrac{2}{16-x^2}+\dfrac{4}{4x+16}\right):\dfrac{1}{4x}\left(x\ne4;x\ne-4;x\ne0\right).\)
\(A=\left(\dfrac{1}{x\left(x-4\right)}+\dfrac{-2}{\left(x+4\right)\left(x-4\right)}+\dfrac{1}{x+4}\right).4x\).
\(A=\dfrac{x+4-2x+x^2-4x}{x\left(x-4\right)\left(x+4\right)}.4x.\)
\(A=\dfrac{x^2-5x+4}{\left(x-4\right)\left(x+4\right)}.4.\)
\(A=\dfrac{\left(x-4\right)\left(x-1\right)}{\left(x-4\right)\left(x+4\right)}.4.\)
\(A=\dfrac{4\left(x-1\right)}{x+4}.\)
\(\frac{\left(x+\frac{1}{x}\right)^4-\left(x^4+\frac{1}{x^4}\right)-2}{\left(x+\frac{1}{x}\right)^4+x^2+\frac{1}{x^2}}\cdot\frac{x^4+1999x^2+1}{2x^2}\)
a,Rút gọn bt
b,tính giá trị của bt biết \(x^2-4x+1=0\)
rút gọn
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) \(\frac{4.\left(x+3\right)^2}{\left(3x+5\right)^2-4x^2}-\frac{x^2-25}{9x^2.\left(2x+5\right)^2}-\frac{\left(2x+3\right)^2-x^2}{\left(4x+15\right)^2-x^2}\)
b: \(=\dfrac{1}{\left(x+1\right)\left(x+2\right)}+\dfrac{1}{\left(x+2\right)\left(x+2\right)}+\dfrac{1}{\left(x+2\right)\left(x+3\right)}\)
\(=\dfrac{\left(x+2\right)\left(x+3\right)+\left(x+1\right)\left(x+3\right)+\left(x+2\right)\left(x+1\right)}{\left(x+2\right)^2\cdot\left(x+1\right)\left(x+3\right)}\)
\(=\dfrac{x^2+5x+6+x^2+4x+3+x^2+3x+2}{\left(x+2\right)^2\cdot\left(x+1\right)\left(x+3\right)}\)
\(=\dfrac{3x^2+12x+11}{\left(x+2\right)^2\cdot\left(x+1\right)\left(x+3\right)}\)
Rút gọn A=\(\frac{\sqrt{x-\sqrt{4x-4}}+\sqrt{x+4\sqrt{4x-4}}}{\sqrt{x^2-4\left(x-1\right)}}.\left(1-\frac{1}{x-1}\right)\)
Rút gọn \(B=\left(x^4-x+\frac{x-3}{x^3+1}\times\frac{\left(x^3-2x^2+2x-1\right)\left(x+1\right)}{x^9+x^7-3x^2-3}+1-\frac{2\left(x+6\right)}{x^2+1}\right)\times\frac{4x^2+6x+1}{\left(x+3\right)\left(4-x\right)}\)
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) \(\left(\frac{3x}{1-3x}+\frac{2x}{3x+1}\right):\frac{6x^2+10x}{1-6x+9x^2}\)