PLEASE HELP answer options:
SF = 1/3
SF = -1/3
SF = 3
SF = -3

Fiona joins a fruit of the month club. the entry cost was $25 and then she pays $18 per month. if she participates for 8 months, how much will she pay in all? how much in 10 months?

Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy?

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.