3(u-3)-7u=15 how do I find out what u is?

Fred has a total of 62 dvd and cd. if the number of cd is three more than two times the number of dvd, how many cd does he have?

Statement: if two distinct planes intersect, then their intersection is a line. which geometry term does the statement represent? defined term postulate theorem undefined term

A, b, c, and d have the coordinates (-8, 1), (-2, 4), (-3, -1), and (-6, 5), respectively. which sentence about the points is true? a. a, b, c, and d lie on the same line. b. and are perpendicular lines. c. and are parallel lines. d. and are intersecting lines but are not perpendicular. e. and are parallel lines.