a group of students was asked about the number of emails they each sent that day the results are 0,0,1,2,3,4,5,6,6,7,8,8,8,9 i will post the other half now​

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.

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.

What adds to be the bottom number but also multiplies to be the top number with 8 on the bottom and 15 on top