4x - 6y = 10 5x + 7y = -2 if you were going to solve this system by elimination by adding the two equations together, what would be a correct first step? a) multiply the first equation by 7 and the bottom by 6. b) multiply the first equation by 5 and the bottom by 4. c) multiply the first equation by -7 and the bottom by 6. d) multiply the first equation by 7 and the bottom by -6.

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

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees

The ratios of boys to girls on a soccer league is 2: 5. if there are 28 boys, how many girls are playing soccer? extra points! will mark as brainiest asap