II. Tự luận
Bài 1:
a. A \(=\dfrac{x^2-4}{x+1}+\dfrac{2}{x+1}:\left(\dfrac{2x-3}{x-1}-\dfrac{2x+1}{x+1}\right)\)
\(=\dfrac{x^2-4}{x+1}+\dfrac{2}{x+1}:\left(\dfrac{2x^2-x-3}{x^2-1}-\dfrac{2x^2-x-1}{x^2-1}\right)\)
\(=\dfrac{x^2-4}{x+1}+\dfrac{2}{x+1}:\left(\dfrac{-2}{x^2-1}\right)\)
\(=\dfrac{x^2-4}{x+1}+\dfrac{2}{x+1}.\dfrac{1-x^2}{2}\)
\(=\dfrac{x^2-4}{x+1}+\dfrac{2-2x^2}{2\left(x+1\right)}\)
\(=\dfrac{2x^2-8}{2\left(x+1\right)}+\dfrac{2-2x^2}{2\left(x+1\right)}\)
\(=\dfrac{-6}{2\left(x+1\right)}\)
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