From the Chapter 8 opener, we have two functions to describe the amount of sulfur dioxide emissions in the United States. For both functions, $x$ is the number of years since 1970 and $y$ (or $f(x)$ or $g(x))$ is the amount of emissions in millions of tons.
$$
f(x)=-0.59 x+32.38 \text { or } g(x)=-0.0045 x^2-0.37 x+30.89
$$
Use this for Exercises 69 through 74. See Section 3.6.
Find $f(50)$ and describe in words what this means.