Joe is riding his bicycle. he takes 6 hours to ride 38.4 kilometers. what is his speed?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Just tell me how to set up the equation.

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?