12 is 33 1/3% of 36 what is the whole

The parabola y = x² - 4 opens: a.) up b.) down c.) right d.) left

For which of the following counts would a binomial probability model not be reasonable? a)the number of people in a classroom born in januaryb) the number of people in a classroom with red hair c) the number of people admitted to a hospital in a day with a particular disease d) the number of heart beats in a one-minute perio.

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36