The difference between these terms is that a monomial has one term, bi has two, tri has three. Once you understand how these equations are built then they become relatively easy to see and distinguish from one another. Now math is not my strong suite so 4 could also be a trinomial but I'm pretty sure it's none of the above. Good luck!
To find the slope of the graph you pick any piece of the line, and divide the vertical difference between its ends by the horizontal difference between its ends. If the graph is distance versus time then the slope represents the speed.
