Jia is skipping a rock across a pond. The sequence {4.2, 3.57, 3.0345, 2.5793, …} describes the height of the rock on each successive skip. Which explicit formula describes this geometric sequence? a)an=3.57(4.2)n−1

b)an=4.2(0.85)n−1

c)an=4.2(0.15)n−1

d)an=0.85(4.2)n-1

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

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

The measure of an angle is 117°. what is the measure of a supplementary angle?