6. Records indicate that x years after the year 2000, the property tax on a four-bedroom home in a suburb of a major city was 7 (x) = 3x + 40x + 1800 dollars. [10 pts.] (a) At what rate was the property tax increasing with respect to time in 2008? (a) (b) What's the average rate of change of the property tax between 2005 and 2008? (b)