Which rational expression represents the sum 1x2−x+1x2+x\frac{1}{x^2-x} + \frac{1}{x^2+x}x2−x1+x2+x1?
2x2−1\frac{2}{x^2-1}x2−12
2xx2−1\frac{2x}{x^2-1}x2−12x
2x(x2−1)\frac{2}{x(x^2-1)}x(x2−1)2
2x2\frac{2}{x^2}x22