Add: 1x−1+1x+1+2x2−1\dfrac{1}{x-1} + \dfrac{1}{x+1} + \dfrac{2}{x^2-1}x−11+x+11+x2−12.
2x+4x2−1\dfrac{2x + 4}{x^2 - 1}x2−12x+4
2x+2x2−1\dfrac{2x + 2}{x^2-1}x2−12x+2
2(x+2)(x−1)(x+1)\dfrac{2(x+2)}{(x-1)(x+1)}(x−1)(x+1)2(x+2)
4x2−1\dfrac{4}{x^2-1}x2−14