Ahelicopter descends at a rate of 450 feet per minute write the equation and sole the change in altitude of the helicopter after 5 minutes?

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Can someone me with this problem i don't understand i need

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