I think you are right so far what i've done comes out to your answer.
        
             
        
        
        
Step-by-step explanation:
the rate of change is officially
(f(x2) - f(x1)) / (x2 - x1)
but for a line function (as we have here) this is totally easy : it is the slope of the line.
and that means it is the factor of x.
in our case this is -3/2.
because the slope of a line is the ratio "y coordinate change / x coordinate change". and that is exactly corresponding to the general rate of change definition above. 
 
        
             
        
        
        
Answer:
23 degrees
Step-by-step explanation:
Find the diagram attached
The sum of angle on the straight line is 180°
103+3x+15+x+10 = 180
128+4x =180
4x = 180-128
4x = 52
x = 52/4
x = 13
The measure of the angle of the intersection between Derby Drive and Rosemont is x+10
= 13+10
= 23 degrees
Hence the measure of the angle is 23 degrees
 
        
             
        
        
        
Answer:
Considering the Law of Cosines:




 
        
             
        
        
        
She was driving an average of 51 mph.