Given the center 
and the radius 
of a circle, its equation is
In your case, the center is (-4,0), and the radius is 2. Plug these values into the generic formula and you'll get the equation.
Answer:
you know you really need to watch what you say that comes out of your mouth
The next bigger ten is 913,620 .
The next smaller ten is 913,600.
913,610 is exactly in the middle between them.
913,610 is already written to the nearest ten.
Dividing the number of tires that should be installed per day which is 400 by the number of working hours which is 8 will give us 50 tires per hour. Assuming that the same mistake will take toll on the workers such that they will have 1 tire mistakenly installed in an hour, they will have 8 erroneous tires in a day. Multiplying this by 5 to make the answer per week will give 40. Out of the 400 x 5 = 2000 tires. The answer would be 2000 - 40 which is equal to 1940. The assumption must be valid.
