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$$\frac{- 6 x + \left(x - 4\right) \left(\left(3 x + 10\right) \left(\frac{1}{x + 5} + \frac{2}{x}\right) + \frac{3 x + 10}{x + 5} - \frac{2 \left(3 x + 5\right)}{x} + \frac{2 \left(3 x + 10\right)}{x}\right) - 20}{x^{3} \left(x + 5\right)^{2}} = 0$$
Solve this equationThe roots of this equation
$$x_{1} = 1 + \frac{16}{\sqrt[3]{\frac{5 \sqrt{209}}{2} + \frac{147}{2}}} + \sqrt[3]{\frac{5 \sqrt{209}}{2} + \frac{147}{2}}$$
You also need to calculate the limits of y '' for arguments seeking to indeterminate points of a function:
Points where there is an indetermination:
$$x_{1} = -5$$
$$x_{2} = 0$$
$$\lim_{x \to -5^-}\left(\frac{- 6 x + \left(x - 4\right) \left(\left(3 x + 10\right) \left(\frac{1}{x + 5} + \frac{2}{x}\right) + \frac{3 x + 10}{x + 5} - \frac{2 \left(3 x + 5\right)}{x} + \frac{2 \left(3 x + 10\right)}{x}\right) - 20}{x^{3} \left(x + 5\right)^{2}}\right) = \infty$$
$$\lim_{x \to -5^+}\left(\frac{- 6 x + \left(x - 4\right) \left(\left(3 x + 10\right) \left(\frac{1}{x + 5} + \frac{2}{x}\right) + \frac{3 x + 10}{x + 5} - \frac{2 \left(3 x + 5\right)}{x} + \frac{2 \left(3 x + 10\right)}{x}\right) - 20}{x^{3} \left(x + 5\right)^{2}}\right) = -\infty$$
- the limits are not equal, so
$$x_{1} = -5$$
- is an inflection point
$$\lim_{x \to 0^-}\left(\frac{- 6 x + \left(x - 4\right) \left(\left(3 x + 10\right) \left(\frac{1}{x + 5} + \frac{2}{x}\right) + \frac{3 x + 10}{x + 5} - \frac{2 \left(3 x + 5\right)}{x} + \frac{2 \left(3 x + 10\right)}{x}\right) - 20}{x^{3} \left(x + 5\right)^{2}}\right) = -\infty$$
$$\lim_{x \to 0^+}\left(\frac{- 6 x + \left(x - 4\right) \left(\left(3 x + 10\right) \left(\frac{1}{x + 5} + \frac{2}{x}\right) + \frac{3 x + 10}{x + 5} - \frac{2 \left(3 x + 5\right)}{x} + \frac{2 \left(3 x + 10\right)}{x}\right) - 20}{x^{3} \left(x + 5\right)^{2}}\right) = -\infty$$
- limits are equal, then skip the corresponding point
Сonvexity and concavity intervals:Let’s find the intervals where the function is convex or concave, for this look at the behaviour of the function at the inflection points:
Concave at the intervals
$$\left[1 + \frac{16}{\sqrt[3]{\frac{5 \sqrt{209}}{2} + \frac{147}{2}}} + \sqrt[3]{\frac{5 \sqrt{209}}{2} + \frac{147}{2}}, \infty\right)$$
Convex at the intervals
$$\left(-\infty, 1 + \frac{16}{\sqrt[3]{\frac{5 \sqrt{209}}{2} + \frac{147}{2}}} + \sqrt[3]{\frac{5 \sqrt{209}}{2} + \frac{147}{2}}\right]$$