Which of the following expressions is equal to -x^2 - 81? a. (-x-9i)(x+9i) b. (-x+9i)(x-9i) c. (-x-9i)(x-9i) d. (x+9i)(x-9i)

Can (2,3 and square root 10) be sides ona right triangle?

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

I’m confused on how to work the pie charts