Ikinda sorta understand this but not completely

To which set of numbers does the number –5 belong? select all that apply. integers natural numbers rational numbers real numbers whole numbers

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

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"