How to calculate percentage?

Given right triangle xyz, which correctly describes the locations of the sides in relation to

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

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10