Simplify: x+1xx−1x\dfrac{x + \dfrac{1}{x}}{x - \dfrac{1}{x}}x−x1x+x1 (assume x≠0,±1x \neq 0, \pm 1x=0,±1).
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x2+1x2−1\dfrac{x^2 + 1}{x^2 - 1}x2−1x2+1
x+1x−1\dfrac{x + 1}{x - 1}x−1x+1
x2−1x2+1\dfrac{x^2 - 1}{x^2 + 1}x2+1x2−1