Marshall's mistake lies in not considering that exponential functions like \( f(x) = 6(1.5)^x \) grow at a faster rate than linear functions like \( g(x) = 5x + 10 \) as \( x \) increases.
The correct response is:
Marshall is only considering a small portion of the domains of the functions. If he went farther to the right on the graph, he would observe that the growth rate of \( f(x) = 6(1.5)^x \) eventually surpasses the growth rate of \( g(x) = 5x + 10 \) for large values of \( x \).
This reflects the characteristic of exponential growth outpacing linear growth in the long run.