Which represents a quadratic function? f(x) = -8x3 - 16x2 - 4x
f(x) = 3/4 x2 + 2x - 5
f(x) = 4/x2 - 2/x + 1
f(x) = 0x2 - 9x + 7

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

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

1yd 1 ft = 1 1/12 1 1/3 1 1/2 1 1/6