Answer:
<em>He would pay $287 if he races 39 times</em>
<em>Thus, the membership fee is $14.</em>
Step-by-step explanation:
<u>Linear Modeling</u>
The situation described in the problem can be modeled as the equation of a line which has the form:
Where y is the cost of the course, x is the number of races, a is the cost per race, and b is the membership fee.
We know the course charges $7 per race, so a=7. Since your friend has raced x=28 times and paid y=210, we can find the value of b:
Operating:
b=14
Thus, the membership fee is $14.
The linear model is now:
If he races x=39 times, your friend would pay:
y=287
He would pay $287 if he races 39 times