Two neighboring towns, Nash Town and Bay Town, were surveyed, and their populations were found to be x 1 3 + 2 x 1 5 and 3 x 1 3 − x 1 5 (in thousands), respectively, where x is the number of years since the towns were founded. (Assume that both towns were founded at the same time.) Question 1 Find the function that gives the total population of both towns.