Help please!! The maximum value of total revenue correspond to a price of

9514 1404 393

  d.  $30

Step-by-step explanation:

When price and demand are linearly related like this, revenue is a quadratic function. Its maximum will be halfway between the prices that give a revenue of 0. Those prices are $60 (where demand is 0) and $0 (where demand is irrelevant). The halfway point is ($60 +0)/2 = $30.

As a check, you can figure revenue for some nearby points.

  at $30, revenue is ($30)(15) = $450

  at $24, revenue is ($24)(18) = $432

  at $36, revenue is ($36)(12) = $432

This confirms revenue is maximized at a price of $30.

walter needs to make at least 5 more cookies but no more than 40. 5 ≥ x ≥ 40;

step-by-step explanation:

walter has to make a minimum of 20 cookies. he already has 15 cookies made, so he must make 5 more to meet the minimum.

the maximum amount of cookies he can make is 55. he already has 15, so he has to make no more than 40 more cookies to meet the maximum.