$$\int\frac{9x+3}{\sqrt{x^{2}+3x}}-4$$
$-\frac{21\ln(|2\sqrt{x\left(x+3\right)}+2x+3|)}{2}+9\sqrt{x\left(x+3\right)}+С$
$\frac{3\left(3x+1\right)}{\sqrt{x\left(x+3\right)}}$
