Primitive of Reciprocal of x squared by a x + b/Proof 2

Theorem

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