\(=\dfrac{4x\left(x+2\right)}{\left(2-x\right)\left(2+x\right)}\cdot\dfrac{2-x}{1-2x}=\dfrac{4x}{1-2x}\)
\(=\dfrac{4x\left(x+2\right)}{\left(2-x\right)\left(2+x\right)}\cdot\dfrac{2-x}{1-2x}=\dfrac{4x}{1-2x}\)
Bài 2 . Thực hiện phép tính
a)\(6x^3\)\(\left(\dfrac{1}{3}x^2-\dfrac{5}{2}-\dfrac{1}{6}\right)\)\(-2x^5\)\(-x^3\)
b)\(\left(x-3\right)\left(x^2+3x-2\right)\)
c)\(\left(4x^3-4x^2-5x+4\right):\left(2x+1\right)\)
Thực hiện phép tính sau:
a) \(2x\left(1+\dfrac{1}{2}x^2-\dfrac{5}{2}x^3\right)\)
b) \(\dfrac{4x}{2x-1}-\dfrac{7x+3}{4x^2-1}\)
thực hiện phép tính
\(\dfrac{x^2-50}{3x^2-9x}:\dfrac{2x^2+10x}{x^2-9}\)
\(\dfrac{-3x^2}{2x+1}:\left(-\dfrac{9}{4x^2-1}\right)\)
thực hiện phép tính
\(\dfrac{x^2-50}{3x^2-9x}\):\(\dfrac{2x^2+10x}{x^2-9}\)
\(\dfrac{-3x^2}{2x+1}:\left(-\dfrac{9}{4x^2-1}\right)\)
Thực hiện phép tính:
a) \(3x.\left(2x^2-3x+4\right)\)
b) \(\left(x+3\right)^2+\left(3x-2\right)\left(x+4\right)\)
c) \(\dfrac{2x-4}{x-1}+\dfrac{2x+2}{x^2-1}\)
Thực hiện phép tính
\(a,\left(1-x\right)^2\)\(+x\left(2-x\right)\)
\(b,\dfrac{x^2+4x+4}{x+2}\)
BT10: Thực hiện phép tính
\(a,-xyz^2\)\(-3xz.yz\)
\(b,-8x^2\)\(y-x.\left(xy\right)\)
\(c,4xy^2\) \(.x-\left(-12x^2y^2\right)\)
\(d,\dfrac{1}{2}x^2y^3-\dfrac{1}{3}x^2y.y^2\)
\(e,3xy\left(x^2y\right)-\dfrac{5}{6}x^3y^2\)
\(f,\dfrac{3}{4}x^4y-\dfrac{1}{6}xy.x^3\)
Thực hiện phép tính:
\(a,\left(x-\dfrac{x^2+y^2}{x+y}\right)\left(\dfrac{1}{y}+\dfrac{2}{x-y}\right)\)
\(b,\left(\dfrac{2}{x^2-1}+\dfrac{x^2-3}{3x^2-1}\right):\left[\dfrac{1}{x}-\dfrac{2x\left(x^2-3\right)}{\left(x^2-1\right)\left(3x^2-1\right)}\right]\)
thực hiện phép tính:
\(\dfrac{1}{x\left(x+1\right)}\)+\(\dfrac{1}{\left(x+1\right)\left(x+2\right)}\)+\(\dfrac{1}{\left(x+2\right)\left(x+3\right)}\)+...+\(\dfrac{1}{\left(x+2013\right)\left(x+2014\right)}\)