Someone please answer these two questions for me

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.

Drag each tile to the correct box. not all tiles will be used. consider the recursively defined function below. create the first five terms of the sequence defined by the given function

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