Answer:
or simplified would be 
Step-by-step explanation:
In order to calculate the rate of change, we must subtract his end position and end time by the starting position and starting time. We are using the -15 feet since it is below the surface area as the starting position and the 10 seconds as the starting time. We make each of these into a fraction and subtract like so...
rate of change
rate of change
= rate of change
Therefore, we can see that the rate of change of the diver is
or simplified would be 
Answer:
1/6? it has the common denominator
number 3 is not congruent but number 4 is because #4 is basically the same thing but you cant really multiply something to question #3 to get those answers.