Answer:
Part 1) 
Part 2) 
Part 3) 
Step-by-step explanation:
<em>Table 1</em>
step 1
Find the slope
take two points from the data in the table
(0,3) and (3,15)
The formula to calculate the slope between two points is equal to

substitute


step 2
Find the linear function in slope intercept form

we have

substitute

<em>Table 2</em>
step 1
Find the slope
take two points from the data in the table
(2,5) and (5,11)
The formula to calculate the slope between two points is equal to

substitute


step 2
Find the linear function in slope intercept form

we have

Solve for b
substitute

therefore

<em>Table 3</em>
step 1
Find the slope
take two points from the data in the table
(5,1) and (8,4)
The formula to calculate the slope between two points is equal to

substitute


step 2
Find the linear function in slope intercept form

we have

Solve for b
substitute

therefore
