Answer
$-\frac{1}{3x}$
Work Step by Step
We factor the expression in the denominator in order to cancel out common factors in the numerator and the denominator:
Step 1: $\frac{9-x^{2}}{3x^{3}-27x}$
Step 2: $\frac{9-x^{2}}{-3x(9-x^{2})}$
Step 3: $\frac{1}{-3x}$
Step 4: $-\frac{1}{3x}$
