Find the expected value of the winnings from a game that has the following payout probability distribution

Which is the completely factored from of xy^3-x^3y

What situation is an example of an observational study

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?