## Functions Modeling Change: A Preparation for Calculus, 5th Edition

$\frac{18}{x^3}$
To divide fractions, take the product of the reciprocal. This leaves $$\frac{3}{x} \cdot \frac{6}{x^2}=\frac{18}{x(x^2)}=\frac{18}{x^{1+2}}=\frac{18}{x^3}$$