The cost function is an illustration of a linear function
The equation of the cost function is C(x) = 35 + 0.5x
The given parameters are:
-- the cost of renting a cooler
--- the rate per bottle
Assume the number of bottles in a cooler is x.
The cost function for the bottles in a cooler would be:

So, we have:

Evaluate the products

Hence, the equation is 
Read more about linear functions at:
brainly.com/question/15602982
Answer:
B he used the incorrect formula for the volume of the prism
Step-by-step explanation:
If you have any questions about the way I solved it, don't hesitate to ask me in the comments below ;)
Given the points A and B
The coordinates of point A = ( 3 , 1 )
The coordinates of point B = (-1 , -1)
The midpoint of AB, is the point C
C will be calculated as following :

so, the midpoint of AB = (1 , 0 )