Primitive of Reciprocal of x squared by a x + b cubed

Theorem

 * $\displaystyle \int \frac {\mathrm d x} {x^2 \left({a x + b}\right)^3} = \frac {-a} {2 b^2 \left({a x + b}\right)^2} - \frac {2 a} {b^3 \left({a x + b}\right)} - \frac 1 {b^3 x} + \frac {3 a} {b^4} \ln \left\vert{\frac {a x + b} x}\right\vert + C$