Let's find the inflection points, we'll need to solve the equation for this
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0$$
(the second derivative equals zero),
the roots of this equation will be the inflection points for the specified function graph:
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = $$
the second derivative$$\frac{\frac{x \left(\left(2 x + 1\right) \left(\frac{1}{x + 2} + \frac{1}{x - 1}\right) - 2 + \frac{2 x + 1}{x + 2} + \frac{2 x + 1}{x - 1}\right)}{x + 2} + 2 - \frac{2 \left(2 x - 1\right) \left(2 x + 1\right)}{\left(x - 1\right) \left(x + 2\right)}}{\left(x - 1\right) \left(x + 2\right)} = 0$$
Solve this equationSolutions are not found,
maybe, the function has no inflections