R(t) = −131t − 749.5 million dollars per year

Question

and the rate of change in the annual operating profit may be modeled by

P(t) = 12t + 76 million dollars per year, where t is the number of years since the end of 1999.
Determine the accumulated change in annual operating costs from the end of 1999 through 2001 by finding the area between these two curves.