Answer:
A. The weekly usage of both coupons is decreasing and approaching a horizontal asymptote as x gets larger.
Explanation:
You can see that f(x) is a decreasing exponential function because the base is 0.75, a value less than 1. The horizontal asymptote is 10, the constant added to the exponential term.
Obviously, g(x) is decreasing. If we assume it is an exponential function, we know there is a horizontal asymptote. (Every exponential function has a horizontal asymptote.)
__
If you use your graphing calculator's exponential regression function, you can find a good model for g(x) is ...
g(x) = 950·0.7^x +12
That is, it is an exponential function that decays faster than f(x), but has a higher horizontal asymptote.
_____
Both functions are decreasing and approaching horizontal asymptotes.