Let x be the number of cars manufactured per day in county A.
Let y be that of cars manufactured per day in county B.
x+y= 39,612
but x= 5y..... equation (1)
So: 5y+y= 39,612
6y= 39,612
y= 6,602 cars
Substitute y= 6,602 in equation (1):
x= 5(6,602)
x= 33,010
So the number manufactured in county A is 33,010 cars and the number manufactured in county B is 6,602 cars.