Why does a positive times a negative give you negative and a negative x negative give you a positive? please use mathematical proofs. thank you.​

Find the value of tan theta if sin theta = 12/13 and theta is in quadrant 2

Which equations represents circles that have a diameter of 12 units and a center that lies on the y-axis? check all that apply

Four airplanes carrying a total of 400 passengersarrive at the detroit airport. the airplanes carry, respectively,50, 80, 110, and 160 passengers. a) one of the 400 passengers is selected uniformly at random. let x denote the number of passengers that were on theairplane carrying the randomly selected passenger. find var(x)for x as given in the problemb) one of the 4 airplane drivers is also selected uniformly atrandom. let y denote the number of passengers on the chosen driver’s airplane. find var(y) for y as given in the problem