How to find the slope of a line given two points?

What are the domain and range of the function? f(x) = -4 (sqrt)x

An unknown number of kids and buses are getting assigned. when assigning 4 kids to each bus, there are 2 kids that aren't placed in a bus. when assigning 8 kids to each bus, there are 2 empty buses. how many total kids are there?

Match the one-to-one functions with the graphs of their inverse functions.