HELP PLEASE!!!!

The amount of people in the city of Blonton is increasing due to children being born and because people are moving to the area.

~The population is increasing due to births by 13% each year and about 2300 people move to the area in any given year.
~The increase due to people moving to the area is represented by the function M(t) = 2300t.
~The population at any time when taking into account new births is found by P(t) = 375,000(1.013)t where 375000 was the initial population and t stands for the number of years after 1990.

If we added these functions together, what would the sum represent?