In how many ways can 81 be written as the sum of three positive perfect squares if the order of the three perfect squares does not matter?

If f(x)=x^3 and g(x)=2x+7 when g(x)=-5

Find the quotient. 50a2 – 98b2 -5a +7b

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