What is the value of the expression below when z=7?
3z-3
A
12
B
18
21
34

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

Can someone me and do the problem plz so i can understand it more better

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 5x^2 + 10x