I have the following indefinite at hand and I'm sure substitution is the only way I should go about solving this, but each time I think I get close, I end up at the same place, which doesn't seem to be the solution according to WolframAlpha.

$$\int \frac{\sqrt{x^2-6x+18}}{x-3}dx$$

I tried to substitute with $t=x-3$ for the denominator and a step after that $u=t^2+9$ for the numerator under the square root, but I would like to hand it over to someone who could perhaps show me a way!