## Precalculus: Mathematics for Calculus, 7th Edition

$$f(\frac{x}{3}) = 2x-18$$ $$\frac{f(x)}{3} = 2x-6$$
For x = $\frac{x}{3}$ $f(\frac{x}{3})= 6(\frac{x}{3}) - 18$ ... multiply and simplify $=2x -18$ _______________ $f(x) = 6x-18$ therefore $\frac{f(x)}{3} = \frac{6x-18}{3}$ ... simplify $=2x -6$