One number is three less than another . their sum is fifteen. find a numbers?

In triangle abc segment de is parallel to the side ac . (the endpoints of segment de lie on the sides ab and bc respectively). find de, if ac=20cm, ab=17cm, and bd=11.9cm;

Find the equation using the point (4,8)

Jennifer taking a quiz and has answered 13 questions so far. if there are 25 questions on jennifer test, how many questions does she have left to answer