Answer:
Part 1) The rate of change is 
Part 2) The initial value is 
Step-by-step explanation:
we know that
The linear equation in slope intercept form is equal to

where
m is the slope or rate of change
b is the y-intercept or initial value
step 1
Find the slope or rate of change
The formula to calculate the slope between two points is equal to

we have the points
(5,12)and (2,6)
substitute the values in the formula



therefore
The rate of change is 
step 2
Find the initial value
we have


substitute in the equation 

solve for b

---> initial value
The linear equation is equal to

The y-intercept or initial value is 2