Answer:
They need to wash 72 cars
Step-by-step explanation:
2000 - 1640 = 360
360/5 = 72
We have the equation:

By arranging this equation in terms of x and y, we have:

By using the method of completing the square, we have:

The center of this circle is:

So the equation that fulfills the statement is:

Finally, the right answer is c)