Which expression is equivalent to 3^7•3^-4

Which best explains why this triangle is or is not a right triangle?

Find the value of the variable and the length of each secant segment.

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.