How do you simplify -2n - (9-10n)

Julia chooses a card at random from her set of cards. what is the probability that the card is labeled cat or hamster?

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?

Write two point-slope equations for the line passing through the points (6, 5) and (3, 1)