(NEED HELP ASAP) a = -9 b = -4

1.) 3ab

2.)4b^2|3b - 7

| is divide
I need it evaluated to a single value

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.

Nine people are going to share a 128-ounces bottle of soda. how many ounces will each person get drink? choose the correct equation and answer for this situation

Suppose you can spend at most $12. create an inequality that represents this restraint. then find at least three ordered pair solutions representing the number of boxes of candy and combos you can buy