Pls help i beg u pls

How do you use the additive inverse to evaluate an expression that uses subtraction in a full sentence

Last year, a state university received 3,560 applications from boys. of those applications, 35 percent were from boys who lived in other states. part a)how many applications did the university receive from boys who lived in other states? part b)applications to the university from boys represented 40percent of all applications. how many applications did the university receive in all? i don't how to do part b so me and plz tell how you got your answer

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?