Simplify -18b^-4 Pliz help, I don’t understand math, especially Algebra II

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

Asquare picture with sides of 32 inches is to be mounted on a square mat with sides of 52 inches. find the area of the mat that will remain uncovered by the picture.

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?