If the average rate of change of g(x) from x = 1 to x = 5 is 17.5, and if the average rate of change of g(x) from x = 5 to x = 10 is 35, then what is the average rate of change of g(x) from x = 1 to x = 10?

Umm, just add them together and divide by 2... 17.5 + 35 = 52.5... Divided by 2...26.25..