Answer:
The formula that will estimate the odometer reading after Bill owned the car for X weeks is: 40,952.5 + 289.95X.
In turn, the number of miles the car had gone when Bill bought it was 40,952.5.
Explanation:
Since Bill bought a used car, and after he'd owned the car for 10 weeks, I noticed that the car's odometer showed that it had gone a total of 43,852 miles (including the mileage on the car when Bill bought it). Subsequently, 30 weeks since Bill bought the car, the odometer shows 49,651 miles. Thus, assuming that Bill drives a consistent amount each week, to develop a formula that will estimate the odometer reading after Bill owned the car for X weeks and determine about how many miles had the car gone when Bill bought it, the following calculations must be performed:
(49.651 - 43.852) / 20 = X
5,799 / 20 = X
289.95 = X
So the average number of miles Bill drives per week is 289.95.
289.95 x 10 = 2,899.5
43,852 - 2,899.5 = 40,952.5
Thus, the formula that will estimate the odometer reading after Bill owned the car for X weeks is: 40,952.5 + 289.95X.
In turn, the number of miles the car had gone when Bill bought it was 40,952.5.