Simplify \[ \frac{3 x+9}{5 x^{2}+15 x} \]

Step 1 ：Define the variable x.

Step 2 ：Define the expression \(\frac{3x + 9}{5x^2 + 15x}\).

Step 3 ：Simplify the expression using algebraic methods.

Step 4 ：The simplified expression is \(\frac{3}{5x}\). This is the simplest form of the expression, and there are no common factors in the numerator and the denominator that can be cancelled out.

Step 5 ：Final Answer: \(\boxed{\frac{3}{5x}}\)