Quick conjugate clarifcation

Consider the function $\displaystyle f(x)=(18x+18h)(\sqrt{15x-3})-18x\sqrt{15x+15h-3}$

If you factor out an $\displaystyle 18x$, then theres still a $\displaystyle (1+18h)$ in front of the first square root. Would the conjugate just be the square roots or would it include the $\displaystyle (1+18h)$?

Thanks for the help!

Edit: Oops, I didn't mean to factor out the $\displaystyle 18x$ but if there were still another term in front of the square root, would the same process apply?