If the price of the early bird session is 2x - 3 and the price of the mid-morning session is 5x + 6, find an expression that represents difference in the price between the mid-morning session and the early bird session?

Answer asap and if you do you will get brainliest. catherine buys a gallon of ice cream from the store. after taking it home, she eats a fifth of a gallon of ice cream. her sister eats some of the ice cream as well. if two-thirds of the original amount of ice cream is left, then what fraction of a gallon of ice cream did her sister eat?