Barbara plotted an elevation below sea level on a number line and labeled it A. She plotted Point B above 0, a distance that is exactly as far from 0 as Point A is. Explain what you know about Point B. WILL MARK BRAINLIEST

Can someone explain the elimination method to me for this problem?

The system of equations graphed below has how many solutions?

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