How to change 2 12/15 into simplest form

The random variable x represents the number of phone calls an author receives in a day, and it has a poisson distribution with a mean of 8.7 calls. what are the possible values of x

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

Explain how you divide powers with like bases.discuss why the bases have to be the same.how are these rules similar to the rules for multiplying powers with like bases.