\(=lim_{x->3^+}\left(\dfrac{5x-6-x^2}{\sqrt{5x-6}+x}\cdot\dfrac{1}{x-3}\right)\)
\(=lim_{x->3^+}\left(\dfrac{-\left(x-2\right)\left(x-3\right)}{\left(x-3\right)\left(\sqrt{5x-6}+x\right)}\right)\)
\(=lim_{x->3^+}\left(\dfrac{-\left(x-2\right)}{\sqrt{5x-6}+x}\right)\)
\(=\dfrac{-\left(3-2\right)}{\sqrt{5\cdot3-6}+3}=\dfrac{-1}{6}\)