` \frac{2}{x^2 - 1} - \frac{1}{x^2 + x} + \frac{x^2 - 3}{x^3 - x} `
` = \frac{2}{(x - 1)(x + 1)} - \frac{1}{x(x + 1)} + \frac{x^2 - 3}{x(x - 1)(x + 1)} `
` = \frac{2x - x + 1 + x^2 - 3}{x(x - 1)(x + 1)} `
` = \frac{x^2 + x - 2}{x(x - 1)(x + 1)} `
` = \frac{x^2 - x + 2x - 2}{x(x - 1)(x + 1)} `
` = \frac{(x - 1)(x + 2)}{x(x - 1)(x + 1)} `
` = \frac{x + 2}{x(x + 1)} `
