Add: 1x+1+1x−1\frac{1}{x+1} + \frac{1}{x-1}x+11+x−11
2xx2−1\frac{2x}{x^2-1}x2−12x
22x\frac{2}{2x}2x2
1(x+1)(x−1)\frac{1}{(x+1)(x-1)}(x+1)(x−1)1
2x2−1\frac{2}{x^2-1}x2−12