I will give Brainiest Answer for whoever helps me!!
I need help adding and subtracting in Scientific Notation... (the ^ means the power)
1. (6 x 10^1) + (9 x 10^1)
2. (7 x 10^0) + (3 x 10^1)
3. (8.8 x 10^2) + ( 3 x 10^2)

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?