a: Ta có: \(\dfrac{1-3x}{2x}-\dfrac{2-3x}{2x-1}-\dfrac{3x-2}{4x^2-2x}\)
\(=\dfrac{\left(1-3x\right)\left(2x-1\right)-2x\left(2-3x\right)-3x+2}{2x\left(2x-1\right)}\)
\(=\dfrac{2x-1+6x^2+3x-4x+6x^2-3x+2}{2x\left(2x-1\right)}\)
\(=\dfrac{12x^2-2x+1}{4x^2-2x}\)
b: Ta có: \(\dfrac{x+2}{x^3-1}-\dfrac{-2}{x^2+x+1}-\dfrac{1}{x+1}\)
\(=\dfrac{x+2+2x-2}{\left(x-1\right)\left(x^2+x+1\right)}-\dfrac{x^3-1}{\left(x+1\right)\left(x-1\right)\left(x^2+x+1\right)}\)
\(=\dfrac{3x^2+3x-x^3+1}{\left(x+1\right)\left(x-1\right)\left(x^2+x+1\right)}\)
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