Answer:
The rate of change is -5
The initial value is 25
Explanation:
Since, this is a linear relation
so, we can select any two points and find equation of line
points are (1,20) and (3,10)
so,


now, we can find slope

now, we can plug values


now, we can use point slope form of line

now, we can plug values

now, we can solve for y

we know that
slope is the rate of change
So, the rate of change is -5
For finding initial value , we can plug x=0 and find y


So, initial value is 25