The function below shows the cost to attend the fair if you ride r rides.
f(r) = 5 + 1.75r
a. What is the y-intercept, and what does it mean?
b. What is the slope, and what does it mean?
c. If Al spent $19.00 at the fair, how many rides did Al ride?
a) The y-intercept of the function is 5. It represents the fixed cost to attend the fair, regardless of the number of rides taken. In this case, the fixed cost is $5.
b) The slope of the function is 1.75. It represents the additional cost (in dollars) for each additional ride taken. In other words, for every ride Al takes, the cost increases by $1.75.
c) To find the number of rides Al took, we can set the cost equal to $19 and solve for r in the equation 5 + 1.75r = 19.
First, we subtract 5 from both sides of the equation to isolate 1.75r:
1.75r = 19 - 5
1.75r = 14
Next, we divide both sides of the equation by 1.75 to solve for r:
r = 14 / 1.75
r = 8
Al rode 8 rides at the fair.