d) Simplify the given expression.

\( \frac{3x}{x+2} \cdot \frac{x-3}{9x^2} : \frac{x-3}{x+2} = \frac{3x}{x+2} \cdot \frac{x-3}{9x^2} \cdot \frac{x+2}{x-3} = \frac{3x \cdot (x-3) \cdot (x+2)}{(x+2) \cdot (x-3) \cdot 9x^2} = \frac{3}{9x} = \frac{1}{3x} \)