Answer
$$ \frac{60}{x^2}$$
Work Step by Step
Recall, one never divides by a fraction. Rather, if we want to divide by a fraction, we multiply by the reciprocal of the fraction. Recall, the reciprocal of a fraction is that fraction with the numerator and the denominator switched. Thus, we find:
$$ \frac{5}{x}\div \frac{x}{12}\\ \frac{5\times \:12}{xx}\\ \frac{60}{x^2}$$