Answer:
Rate of change for the linear relationship modeled is 
Step-by-step explanation:
As the there is a linear relationship in the points, so all these points will be on a single straight line. Hence the slope will be same throughout all the points.
We know that, the slope of the line joining (x₁, y₁) and (x₂, y₂) is,

Putting the points as (-1, 10) and (1, 9), we get



Rate of change is the slope of the line joining all these points.
subtract 5 from both sides. -1.6r=-5 divide both sides by-1.6. r=-5/-1.6 simp;ify-5/1.6 to 3.125. r =3.125
4+8 is 12 so yes it is correct!!!
C - 7.6 = -4
c = -4 + 7.6
c = 3.6