ANSWER
12000x + 40000
Step-by-step explanation
The car already has 40,000 miles on its odometer.
The average owner will drive 12,000 miles per year.
Let the number of years the car is driven be x.
Let the distance the car is driven be f(x).
A linear function is generally written as:
f(x) = mx + b
where m = slope
b = y intercept
The slope describes the rate of change of the values of a function with respect to x values (input values).
It is basically the average rate of change of the function.
From the question given, we have that 12,000 miles is the average miles driven per year.
This means that the slope is 12,000
The y intercept describes the value of a function before any value is put into it.
It is the value of a function at x = 0.
Since the car already has 40000 miles, it means the y intercept is 40000.
Therefore, the equation is:
f(x) = 12000x + 40000