At the end of 2000, mary had 47 cds in her music collection. at the end of 2003, she had 83 cds. she collected an equal number of cds each year between 2000 and 2003.
what is the rate of change in the number of cds in mary’s collection between 2000 and 2003?

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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.

How do you write something in scientific notation?