Find the Circumference of a circle with a Diameter of 9 inches Group of answer choices 9 pi inches 9 pi inches^2 9 pi inches^3 108 pi inches

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.

If w = 6 units, x = 3 units, and y = 5 units, what is the surface area of the figure? 168 units2 240 units2 144 units2 96 units2

Find the zeros of each function. f(x) = x^2 + 5x - 6